291 (number)
| ||||
|---|---|---|---|---|
| Cardinal | two hundred ninety-one | |||
| Ordinal | 291st (two hundred ninety-first) | |||
| Factorization | 3 × 97 | |||
| Divisors | 1, 3, 97, 291 | |||
| Greek numeral | ΣϞΑ´ | |||
| Roman numeral | CCXCI, ccxci | |||
| Binary | 1001000112 | |||
| Ternary | 1012103 | |||
| Senary | 12036 | |||
| Octal | 4438 | |||
| Duodecimal | 20312 | |||
| Hexadecimal | 12316 | |||
291 is the natural number following 290 and preceding 292.
In mathematics
[edit]- 291 is an odd composite number with two prime factors.[1]
- 291 is a semiprime number meaning that it has 2 prime factors.[2]
- 291 can be written as the sum of the nth prime plus n. It is the 52nd prime (239) plus 52.[3]
- 291 is one of the positions of “c” in the tribonacci word abacabaab… defined by a->ab, b->ac, c->a.[4]
- 291 is the sum of six 4th powers. It is the sum of 4⁴+2⁴+2⁴+1⁴+1⁴+1⁴.[5]
References
[edit]- ^ "Facts about the integer". mathworld.wolfram.com.
- ^ "Semiprime". mathworld.wolfram.com.
- ^ Sloane, N. J. A. (ed.). "Sequence A014688". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A003146 (Positions of letter c in the tribonacci word abacabaabacababac... generated by a->ab, b->ac, c->a (cf. A092782))". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A003340 (Numbers that are the sum of 6 positive 4th powers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
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