Number

61,681

61,681 is a prime, odd.

61,681 (sixty-one thousand six hundred eighty-one) is an odd 5-digit number. It is a prime number — divisible only by 1 and itself. Written other ways, in hexadecimal, 0xF0F1.

Arithmetic Number Cube-Free Deficient Number Flippable Odious Number Prime Pythagorean Prime Recamán's Sequence Sexy Prime Squarefree

Interestingness

★ ★ ★ ★ ★

8 notable facts · grade A

61,669 61,670 61,671 61,672 61,673 61,674 61,675 61,676 61,677 61,678 61,679 61,680 61,681 61,682 61,683 61,684 61,685 61,686 61,687 61,688 61,689 61,690 61,691 61,692 61,693

less more

Properties

Parity: Odd
Digit count: 5
Digit sum: 22
Digit product: 288
Digital root: 4
Palindrome: No
Bit width: 16 bits
Reversed: 18,616
Flips to (rotate 180°): 18,919
Recamán's sequence: a(49,086) = 61,681
Square (n²): 3,804,545,761
Cube (n³): 234,668,187,084,241
Divisor count: 2
σ(n) — sum of divisors: 61,682
φ(n) — Euler's totient: 61,680

Primality

61,681 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)

1 · 61681

Aliquot sum (sum of proper divisors): 1

Factor pairs (a × b = 61,681)

1 × 61681

First multiples

61,681 · 123,362 (double) · 185,043 · 246,724 · 308,405 · 370,086 · 431,767 · 493,448 · 555,129 · 616,810

Sums & aliquot sequence

As a sum of two squares: 60² + 241²

As consecutive integers: 30,840 + 30,841

Continued fraction of √n

√61,681 = [248; (2, 1, 4, 9, 6, 2, 1, 11, 1, 2, 1, 3, 7, 2, 1, 2, 54, 1, 4, 2, 10, 8, 1, 3, …)]

Representations

In words: sixty-one thousand six hundred eighty-one
Ordinal: 61681st
Binary: 1111000011110001
Octal: 170361
Hexadecimal: 0xF0F1
Base64: 8PE=
One's complement: 3,854 (16-bit)
Scientific notation: 6.1681 × 10⁴
As a duration: 61,681 s = 17 hours, 8 minutes, 1 second

In other bases

ternary (3) 10010121111

quaternary (4) 33003301

quinary (5) 3433211

senary (6) 1153321

septenary (7) 344554

nonary (9) 103544

undecimal (11) 42384

duodecimal (12) 2b841

tridecimal (13) 220c9

tetradecimal (14) 1869b

pentadecimal (15) 13421

As an angle

61,681° = 171 × 360° + 121°

121° ≈ 2.112 rad

Compass bearing: ESE (east-southeast)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒁹
Egyptian hieroglyphic: 𓂍𓂍𓂍𓂍𓂍𓂍𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺
Greek (Milesian): ͵ξαχπαʹ
Mayan (base 20): 𝋧·𝋮·𝋤·𝋡
Chinese: 六萬一千六百八十一
Chinese (financial): 陸萬壹仟陸佰捌拾壹

In other modern scripts

Eastern Arabic ٦١٦٨١ Devanagari ६१६८१ Bengali ৬১৬৮১ Tamil ௬௧௬௮௧ Thai ๖๑๖๘๑ Tibetan ༦༡༦༨༡ Khmer ៦១៦៨១ Lao ໖໑໖໘໑ Burmese ၆၁၆၈၁

Digit at this position in famous constants

π — Pi (π): Digit 61,681 = 0
e — Euler's number (e): Digit 61,681 = 2
φ — Golden ratio (φ): Digit 61,681 = 4
√2 — Pythagoras's (√2): Digit 61,681 = 5
ln 2 — Natural log of 2: Digit 61,681 = 2
γ — Euler-Mascheroni (γ): Digit 61,681 = 9

Also seen as

Prime neighborhood

Adjacent primes:

Previous prime: 61,673 (gap of 8)
Next prime: 61,687 (gap of 6)

Pair status: sexy with 61687.

Hex color

#00F0F1

RGB(0, 240, 241)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.240.241.

Address: 0.0.240.241
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.240.241

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

Position in π

The digit sequence 61681 first appears in π at position 311,177 of the decimal expansion (the 311,177ordinal-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.

Look up 61681 on Pi Search ↗