# 231 (number)

 ← 230 231 232 →
Cardinaltwo hundred thirty-one
Ordinal231st
(two hundred thirty-first)
Factorization3 × 7 × 11
Greek numeralΣΛΑ´
Roman numeralCCXXXI
Binary111001112
Ternary221203
Octal3478
Duodecimal17312

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.