231256640 has 56 divisors (see below), whose sum is σ = 552282360. Its totient is φ = 92233728.

The previous prime is 231256637. The next prime is 231256667. The reversal of 231256640 is 46652132.

It can be written as a sum of positive squares in 4 ways, for example, as 3125824 + 228130816 = 1768^2 + 15104^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 137726 + ... + 139394.

It is an arithmetic number, because the mean of its divisors is an integer number (9862185).

Almost surely, 2^231256640 is an apocalyptic number.

231256640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 231256640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (276141180).

231256640 is an abundant number, since it is smaller than the sum of its proper divisors (321025720).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

231256640 is a wasteful number, since it uses less digits than its factorization.

231256640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2119 (or 2109 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 231256640 is about 15207.1246460335. The cubic root of 231256640 is about 613.8063878296.

The spelling of 231256640 in words is "two hundred thirty-one million, two hundred fifty-six thousand, six hundred forty".