129,720
129,720 is a composite number, even.
129,720 (one hundred twenty-nine thousand seven hundred twenty) is an even 6-digit number. It is a composite number with 64 divisors, and factors as 2³ × 3 × 5 × 23 × 47. Its proper divisors sum to 285,000, more than the number itself, making it an abundant number. Written other ways, in hexadecimal, 0x1FAB8.
Interestingness
Properties
- Parity
- Even
- Digit count
- 6
- Digit sum
- 21
- Digit product
- 0
- Digital root
- 3
- Palindrome
- No
- Bit width
- 17 bits
- Reversed
- 27,921
- Recamán's sequence
- a(497,063) = 129,720
- Square (n²)
- 16,827,278,400
- Cube (n³)
- 2,182,834,554,048,000
- Divisor count
- 64
- σ(n) — sum of divisors
- 414,720
- φ(n) — Euler's totient
- 32,384
- Sum of prime factors
- 84
Primality
Prime factorization: 2 3 × 3 × 5 × 23 × 47
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√129,720 = [360; (6, 720)]
Period length 2 — the block in parentheses repeats forever.
Representations
- In words
- one hundred twenty-nine thousand seven hundred twenty
- Ordinal
- 129720th
- Binary
- 11111101010111000
- Octal
- 375270
- Hexadecimal
- 0x1FAB8
- Base64
- Afq4
- One's complement
- 4,294,837,575 (32-bit)
- Scientific notation
- 1.2972 × 10⁵
- As a duration
- 129,720 s = 1 day, 12 hours, 2 minutes
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹 𒁹𒁹 ·
- Egyptian hieroglyphic
- 𓆐𓂍𓂍𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆
- Greek (Milesian)
- ͵ρκθψκʹ
- Mayan (base 20)
- 𝋰·𝋤·𝋦·𝋠
- Chinese
- 一十二萬九千七百二十
- Chinese (financial)
- 壹拾貳萬玖仟柒佰貳拾
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 129720, here are decompositions:
- 13 + 129707 = 129720
- 79 + 129641 = 129720
- 89 + 129631 = 129720
- 113 + 129607 = 129720
- 127 + 129593 = 129720
- 131 + 129589 = 129720
- 139 + 129581 = 129720
- 167 + 129553 = 129720
Showing the first eight; more decompositions exist.
UTF-8 encoding: F0 9F AA B8 (4 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.1.250.184.
- Address
- 0.1.250.184
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.1.250.184
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 129,720 and was likely granted around 1872.
Patent numbers below 100,000 are excluded as too ambiguous; modern numbering currently reaches roughly 12.5 million.
The digit sequence 129720 first appears in π at position 962,010 of the decimal expansion (the 962,010ordinal-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
- Babylonian numerals — The base-60 cuneiform system that gave us 60 minutes, 60 seconds, and 360°.