133 (number)
| ||||
|---|---|---|---|---|
| Cardinal | one hundred thirty-three | |||
| Ordinal | 133rd (one hundred thirty-third) | |||
| Factorization | 7 × 19 | |||
| Divisors | 1, 7, 19, 133 | |||
| Greek numeral | ΡΛΓ´ | |||
| Roman numeral | CXXXIII, cxxxiii | |||
| Binary | 100001012 | |||
| Ternary | 112213 | |||
| Senary | 3416 | |||
| Octal | 2058 | |||
| Duodecimal | B112 | |||
| Hexadecimal | 8516 | |||
133 (one hundred [and] thirty-three) is the natural number following 132 and preceding 134.
In mathematics
[edit]133 is an n whose divisors (excluding n itself) added up divide φ(n). It is an octagonal number[1] and a happy number.[2]
133 is a Harshad number, because it is divisible by the sum of its digits.
133 is a repdigit in base 11 (111) and base 18 (77), whilst in base 20 it is a cyclic number formed from the reciprocal of the number three.
133 is a semiprime: a product of two prime numbers, namely 7 and 19. Since those prime factors are Gaussian primes, this means that 133 is a Blum integer.
133 is the number of compositions of 13 into distinct parts.[3]
References
[edit]- ^ "Sloane's A000567 : Octagonal numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-27.
- ^ "Sloane's A007770 : Happy numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-27.
- ^ Sloane, N. J. A. (ed.). "Sequence A032020 (Number of compositions (ordered partitions) of n into distinct parts)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-24.