Live analysis

2,491

2,491 is a composite number, odd.

This number doesn't have a permanent NumberWiki page yet — what you see below is computed live. Pages get added to the permanent index when they're notable (years, primes, curated, etc.).

2,491 (two thousand four hundred ninety-one) is an odd 4-digit number. It is a composite number with 4 divisors, and factors as 47 × 53. Written other ways, in Roman numerals it is MMCDXCI and in binary, 100110111011.

Arithmetic Number Cube-Free Deficient Number Evil Number Recamán's Sequence Semiprime Squarefree

Interestingness

★ ★ ★ ☆ ☆

5 notable facts · grade C

2,479 2,480 2,481 2,482 2,483 2,484 2,485 2,486 2,487 2,488 2,489 2,490 2,491 2,492 2,493 2,494 2,495 2,496 2,497 2,498 2,499 2,500 2,501 2,502 2,503

less more

Properties

Parity: Odd
Digit count: 4
Digit sum: 16
Digit product: 72
Digital root: 7
Palindrome: No
Bit width: 12 bits
Reversed: 1,942
Recamán's sequence: a(2,957) = 2,491
Square (n²): 6,205,081
Cube (n³): 15,456,856,771
Divisor count: 4
σ(n) — sum of divisors: 2,592
φ(n) — Euler's totient: 2,392
Sum of prime factors: 100

Primality

Prime factorization: 47 × 53

Nearest primes: 2,477 (−14) · 2,503 (+12)

Divisors & multiples

All divisors (4)

1 · 47 · 53 · 2491

Aliquot sum (sum of proper divisors): 101

Factor pairs (a × b = 2,491)

1 × 2491

47 × 53

First multiples

2,491 · 4,982 (double) · 7,473 · 9,964 · 12,455 · 14,946 · 17,437 · 19,928 · 22,419 · 24,910

Sums & aliquot sequence

As consecutive integers: 1,245 + 1,246 30 + 31 + … + 76 21 + 22 + … + 73

Aliquot sequence: 2,491 → 101 → 1 → 0 — terminates at zero

Continued fraction of √n

√2,491 = [49; (1, 10, 9, 1, 8, 5, 1, 3, 6, 2, 1, 1, 6, 16, 2, 16, 6, 1, 1, 2, 6, 3, 1, 5, …)]

Period length 30 — the block in parentheses repeats forever.

Representations

In words: two thousand four hundred ninety-one
Ordinal: 2491st
Roman numeral: MMCDXCI
Binary: 100110111011
Octal: 4673
Hexadecimal: 0x9BB
Base64: Cbs=
One's complement: 63,044 (16-bit)
Scientific notation: 2.491 × 10³
As a duration: 2,491 s = 41 minutes, 31 seconds

In other bases

ternary (3) 10102021

quaternary (4) 212323

quinary (5) 34431

senary (6) 15311

septenary (7) 10156

nonary (9) 3367

undecimal (11) 1965

duodecimal (12) 1537

tridecimal (13) 1198

tetradecimal (14) c9d

pentadecimal (15) b11

As an angle

2,491° = 6 × 360° + 331°

331° ≈ 5.777 rad

Compass bearing: NNW (north-northwest)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒌋𒌋𒌋𒌋𒁹 𒌋𒌋𒌋𒁹
Egyptian hieroglyphic: 𓆼𓆼𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺
Greek (Milesian): ͵βυϟαʹ
Mayan (base 20): 𝋦·𝋤·𝋫
Chinese: 二千四百九十一
Chinese (financial): 貳仟肆佰玖拾壹

In other modern scripts

Eastern Arabic ٢٤٩١ Devanagari २४९१ Bengali ২৪৯১ Tamil ௨௪௯௧ Thai ๒๔๙๑ Tibetan ༢༤༩༡ Khmer ២៤៩១ Lao ໒໔໙໑ Burmese ၂၄၉၁

Digit at this position in famous constants

π — Pi (π): Digit 2,491 = 8
e — Euler's number (e): Digit 2,491 = 6
φ — Golden ratio (φ): Digit 2,491 = 5
√2 — Pythagoras's (√2): Digit 2,491 = 2
ln 2 — Natural log of 2: Digit 2,491 = 8
γ — Euler-Mascheroni (γ): Digit 2,491 = 9

Also seen as

Hex color

#0009BB

RGB(0, 9, 187)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.9.187.

Address: 0.0.9.187
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.9.187

Unspecified address (0.0.0.0/8) — "this network" placeholder.

Musical pitch

Heard as a frequency, 2,491 Hz is closest to:

Concert pitch (A4 = 440 Hz): D♯7 (2489 Hz, +1¢)
Scientific pitch (C4 = 256 Hz): D♯7 (2435.5 Hz, +39¢)
Baroque pitch (A4 = 415 Hz): E7 (2487.2 Hz, +3¢)

Position in π

The digit sequence 2491 first appears in π at position 292 of the decimal expansion (the 292ordinal-suffix:nd digit after the integer 3).

Search range: the first 1,000,000 fractional digits of π. Any 6-digit-or-shorter string is virtually guaranteed to appear in there — the more interesting signal is the position.

Look up 2491 on Pi Search ↗