161,221
161,221 is a prime, odd.
161,221 (one hundred sixty-one thousand two hundred twenty-one) is an odd 6-digit number. It is a prime number — divisible only by 1 and itself. Written other ways, in hexadecimal, 0x275C5.
Interestingness
Properties
- Parity
- Odd
- Digit count
- 6
- Digit sum
- 13
- Digit product
- 24
- Digital root
- 4
- Palindrome
- No
- Bit width
- 18 bits
- Reversed
- 122,161
- Recamán's sequence
- a(199,714) = 161,221
- Square (n²)
- 25,992,210,841
- Cube (n³)
- 4,190,490,223,996,861
- Divisor count
- 2
- σ(n) — sum of divisors
- 161,222
- φ(n) — Euler's totient
- 161,220
Primality
161,221 is prime. It has exactly two divisors: 1 and itself.
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√161,221 = [401; (1, 1, 10, 4, 1, 4, 1, 13, 1, 3, 2, 2, 4, 2, 5, 2, 2, 2, 1, 3, 1, 1, 5, 2, …)]
Representations
- In words
- one hundred sixty-one thousand two hundred twenty-one
- Ordinal
- 161221st
- Binary
- 100111010111000101
- Octal
- 472705
- Hexadecimal
- 0x275C5
- Base64
- AnXF
- One's complement
- 4,294,806,074 (32-bit)
- Scientific notation
- 1.61221 × 10⁵
- As a duration
- 161,221 s = 1 day, 20 hours, 47 minutes, 1 second
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒁹
- Egyptian hieroglyphic
- 𓆐𓂍𓂍𓂍𓂍𓂍𓂍𓆼𓍢𓍢𓎆𓎆𓏺
- Greek (Milesian)
- ͵ρξασκαʹ
- Chinese
- 一十六萬一千二百二十一
- Chinese (financial)
- 壹拾陸萬壹仟貳佰貳拾壹
Also seen as
UTF-8 encoding: F0 A7 97 85 (4 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.2.117.197.
- Address
- 0.2.117.197
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.2.117.197
Unspecified address (0.0.0.0/8) — "this network" placeholder.
This number falls in the range of US utility patent numbers. If it's a patent, it would be issued as US 161,221 and was likely granted around 1874.
Patent numbers below 100,000 are excluded as too ambiguous; modern numbering currently reaches roughly 12.5 million.
The digit sequence 161221 first appears in π at position 576,307 of the decimal expansion (the 576,307ordinal-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.
- Egyptian hieroglyphic numerals — Seven hieroglyphs for every power of ten, from a single stroke to a million.