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Number

2,621

2,621 is a prime, odd.

2,621 (two thousand six hundred twenty-one) is an odd 4-digit number. It is a prime number — divisible only by 1 and itself. Written other ways, in Roman numerals it is MMDCXXI and in binary, 101000111101.

Arithmetic Number Chen Prime Cousin Prime Cube-Free Deficient Number Odious Number Pernicious Number Prime Pythagorean Prime Recamán's Sequence Squarefree

Interestingness

Properties

Parity
Odd
Digit count
4
Digit sum
11
Digit product
24
Digital root
2
Palindrome
No
Bit width
12 bits
Reversed
1,262
Recamán's sequence
a(7,390) = 2,621
Square (n²)
6,869,641
Cube (n³)
18,005,329,061
Divisor count
2
σ(n) — sum of divisors
2,622
φ(n) — Euler's totient
2,620

Primality

2,621 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 2621
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 2,621)
1 × 2621
First multiples
2,621 · 5,242 (double) · 7,863 · 10,484 · 13,105 · 15,726 · 18,347 · 20,968 · 23,589 · 26,210

Sums & aliquot sequence

As a sum of two squares: 11² + 50²
As consecutive integers: 1,310 + 1,311

Continued fraction of √n

√2,621 = [51; (5, 9, 9, 5, 102)]

Period length 5 — the block in parentheses repeats forever.

Representations

In words
two thousand six hundred twenty-one
Ordinal
2621st
Roman numeral
MMDCXXI
Binary
101000111101
Octal
5075
Hexadecimal
0xA3D
Base64
Cj0=
One's complement
62,914 (16-bit)
Scientific notation
2.621 × 10³
As a duration
2,621 s = 43 minutes, 41 seconds
In other bases
ternary (3) 10121002
quaternary (4) 220331
quinary (5) 40441
senary (6) 20045
septenary (7) 10433
nonary (9) 3532
undecimal (11) 1a73
duodecimal (12) 1625
tridecimal (13) 1268
tetradecimal (14) d53
pentadecimal (15) b9b
Palindromic in base 15

As an angle

2,621° = 7 × 360° + 101°
101° ≈ 1.763 rad
Compass bearing: E (east)

Historical numeral systems

Babylonian (base 60)
𒌋𒌋𒌋𒌋𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹
Egyptian hieroglyphic
𓆼𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓏺
Greek (Milesian)
͵βχκαʹ
Mayan (base 20)
𝋦·𝋫·𝋡
Chinese
二千六百二十一
Chinese (financial)
貳仟陸佰貳拾壹
In other modern scripts
Eastern Arabic ٢٦٢١ Devanagari २६२१ Bengali ২৬২১ Tamil ௨௬௨௧ Thai ๒๖๒๑ Tibetan ༢༦༢༡ Khmer ២៦២១ Lao ໒໖໒໑ Burmese ၂၆၂၁

Digit at this position in famous constants

π — Pi (π)
Digit 2,621 = 3
e — Euler's number (e)
Digit 2,621 = 6
φ — Golden ratio (φ)
Digit 2,621 = 3
√2 — Pythagoras's (√2)
Digit 2,621 = 4
ln 2 — Natural log of 2
Digit 2,621 = 5
γ — Euler-Mascheroni (γ)
Digit 2,621 = 7

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 2,617 (gap of 4)
  • Next prime: 2,633 (gap of 12)

Pair status: cousin with 2617.

Hex color
#000A3D
RGB(0, 10, 61)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.10.61.

Address
0.0.10.61
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.10.61

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

Musical pitch

Heard as a frequency, 2,621 Hz is closest to:

  • Concert pitch (A4 = 440 Hz): E7 (2637 Hz, -11¢)
  • Scientific pitch (C4 = 256 Hz): E7 (2580.3 Hz, +27¢)
  • Baroque pitch (A4 = 415 Hz): F7 (2635.1 Hz, -9¢)
Position in π

The digit sequence 2621 first appears in π at position 14,034 of the decimal expansion (the 14,034ordinal-suffix:th 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.

Related reading

  • Prime numbers — The building blocks of arithmetic: what primes are, why they matter, and how we find them.
  • Mayan numerals — Vigesimal dots-and-bars with a shell zero — one of the earliest true zeros.