Number
21,397
21,397 is a prime, odd.
Properties
- Parity
- Odd
- Digit count
- 5
- Digit sum
- 22
- Digit product
- 378
- Digital root
- 4
- Palindrome
- No
- Bit width
- 15 bits
- Reversed
- 79,312
- Recamán's sequence
- a(41,045) = 21,397
- Square (n²)
- 457,831,609
- Cube (n³)
- 9,796,222,937,773
- Divisor count
- 2
- σ(n) — sum of divisors
- 21,398
- φ(n) — Euler's totient
- 21,396
Primality
21,397 is prime. It has exactly two divisors: 1 and itself.
Divisors & multiples
Aliquot sum (sum of proper divisors):
1
First multiples
21,397
·
42,794
(double)
·
64,191
·
85,588
·
106,985
·
128,382
·
149,779
·
171,176
·
192,573
·
213,970
Sums & aliquot sequence
As a sum of two squares:
9² + 146²
As consecutive integers:
10,698 + 10,699
Representations
- In words
- twenty-one thousand three hundred ninety-seven
- Ordinal
- 21397th
- Binary
- 101001110010101
- Octal
- 51625
- Hexadecimal
- 0x5395
- Base64
- U5U=
- One's complement
- 44,138 (16-bit)
In other bases
ternary (3)
1002100111
quaternary (4)
11032111
quinary (5)
1141042
senary (6)
243021
septenary (7)
116245
nonary (9)
32314
undecimal (11)
15092
duodecimal (12)
10471
tridecimal (13)
997c
tetradecimal (14)
7b25
pentadecimal (15)
6517
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓂍𓂍𓆼𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- ͵κατϟζʹ
- Mayan (base 20)
- 𝋢·𝋭·𝋩·𝋱
- Chinese
- 二萬一千三百九十七
- Chinese (financial)
- 貳萬壹仟參佰玖拾柒
In other modern scripts
Eastern Arabic
٢١٣٩٧
Devanagari
२१३९७
Bengali
২১৩৯৭
Tamil
௨௧௩௯௭
Thai
๒๑๓๙๗
Tibetan
༢༡༣༩༧
Khmer
២១៣៩៧
Lao
໒໑໓໙໗
Burmese
၂၁၃၉၇
Digit at this position in famous constants
- π — Pi (π)
- Digit 21,397 = 1
- e — Euler's number (e)
- Digit 21,397 = 5
- φ — Golden ratio (φ)
- Digit 21,397 = 8
- √2 — Pythagoras's (√2)
- Digit 21,397 = 3
- ln 2 — Natural log of 2
- Digit 21,397 = 4
- γ — Euler-Mascheroni (γ)
- Digit 21,397 = 7
Also seen as
Prime neighborhood
Unicode codepoint
厕
CJK Unified Ideograph-5395
U+5395
Other letter (Lo)
UTF-8 encoding: E5 8E 95 (3 bytes).
Hex color
#005395
RGB(0, 83, 149)
IPv4 address
As an unsigned 32-bit integer, this is the IPv4 address 0.0.83.149.
- Address
- 0.0.83.149
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.83.149
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Position in π
The digit sequence 21397 first appears in π at position 26,837 of the decimal expansion (the 26,837ordinal-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.