# 231 (number)

 ← 230 231 232 →
Cardinal two hundred thirty-one
Ordinal 231st
(two hundred thirty-first)
Factorization 3 × 7 × 11
Greek numeral ΣΛΑ´
Roman numeral CCXXXI
Binary 111001112
Ternary 221203
Quaternary 32134
Quinary 14115
Senary 10236
Octal 3478
Duodecimal 17312
Vigesimal BB20
Base 36 6F36

231 (two hundred [and] thirty-one) is the natural number following 230 and preceding 232.

## In mathematics

Two hundred [and] thirty-one 231 = 3·7·11, sphenic number, triangular number, hexagonal number, octahedral number,[1] centered octahedral number,[2] the number of integer partitions of 16, Mertens function returns 0,[3] and is the number of cubic inches in a U.S. liquid gallon.

231 is:

## References

1. ^ "Sloane's A005900 : Octahedral numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-24.
2. ^ "Sloane's A001845 : Centered octahedral numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-24.
3. ^ "Sloane's A028442 : Numbers n such that Mertens' function is zero". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-24.