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Number

42,821

42,821 is a prime, odd.

Arithmetic Number Deficient Number Evil Number Prime Pythagorean Prime Recamán's Sequence Self Number Sophie Germain Prime Squarefree

Properties

Parity
Odd
Digit count
5
Digit sum
17
Digit product
128
Digital root
8
Palindrome
No
Bit width
16 bits
Reversed
12,824
Recamán's sequence
a(72,950) = 42,821
Square (n²)
1,833,638,041
Cube (n³)
78,518,214,553,661
Divisor count
2
σ(n) — sum of divisors
42,822
φ(n) — Euler's totient
42,820

Primality

42,821 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 42821
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 42,821)
1 × 42821
First multiples
42,821 · 85,642 (double) · 128,463 · 171,284 · 214,105 · 256,926 · 299,747 · 342,568 · 385,389 · 428,210

Sums & aliquot sequence

As a sum of two squares: 130² + 161²
As consecutive integers: 21,410 + 21,411

Representations

In words
forty-two thousand eight hundred twenty-one
Ordinal
42821st
Binary
1010011101000101
Octal
123505
Hexadecimal
0xA745
Base64
p0U=
One's complement
22,714 (16-bit)
In other bases
ternary (3) 2011201222
quaternary (4) 22131011
quinary (5) 2332241
senary (6) 530125
septenary (7) 235562
nonary (9) 64658
undecimal (11) 2a199
duodecimal (12) 20945
tridecimal (13) 1664c
tetradecimal (14) 11869
pentadecimal (15) ca4b

Historical numeral systems

Babylonian (base 60)
𒌋𒁹 𒌋𒌋𒌋𒌋𒌋𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹
Egyptian hieroglyphic
𓂍𓂍𓂍𓂍𓆼𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓏺
Greek (Milesian)
͵μβωκαʹ
Mayan (base 20)
𝋥·𝋧·𝋡·𝋡
Chinese
四萬二千八百二十一
Chinese (financial)
肆萬貳仟捌佰貳拾壹
In other modern scripts
Eastern Arabic ٤٢٨٢١ Devanagari ४२८२१ Bengali ৪২৮২১ Tamil ௪௨௮௨௧ Thai ๔๒๘๒๑ Tibetan ༤༢༨༢༡ Khmer ៤២៨២១ Lao ໔໒໘໒໑ Burmese ၄၂၈၂၁

Digit at this position in famous constants

π — Pi (π)
Digit 42,821 = 9
e — Euler's number (e)
Digit 42,821 = 2
φ — Golden ratio (φ)
Digit 42,821 = 8
√2 — Pythagoras's (√2)
Digit 42,821 = 9
ln 2 — Natural log of 2
Digit 42,821 = 6
γ — Euler-Mascheroni (γ)
Digit 42,821 = 4

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 42,797 (gap of 24)
  • Next prime: 42,829 (gap of 8)
Unicode codepoint
Latin Small Letter K With Stroke And Diagonal Stroke
U+A745
Lowercase letter (Ll)

UTF-8 encoding: EA 9D 85 (3 bytes).

Hex color
#00A745
RGB(0, 167, 69)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.167.69.

Address
0.0.167.69
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.167.69

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

Position in π

The digit sequence 42821 first appears in π at position 67,689 of the decimal expansion (the 67,689ordinal-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.