231215240 has 32 divisors (see below), whose sum is σ = 521662680. Its totient is φ = 92232192.

The previous prime is 231215227. The next prime is 231215261. The reversal of 231215240 is 42512132.

It can be written as a sum of positive squares in 4 ways, for example, as 226863844 + 4351396 = 15062^2 + 2086^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7172 + ... + 22668.

Almost surely, 2^231215240 is an apocalyptic number.

231215240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

231215240 is an abundant number, since it is smaller than the sum of its proper divisors (290447440).

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

231215240 is a wasteful number, since it uses less digits than its factorization.

231215240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15881 (or 15877 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 231215240 is about 15205.7633810342. The cubic root of 231215240 is about 613.7697573844.

Adding to 231215240 its reverse (42512132), we get a palindrome (273727372).

The spelling of 231215240 in words is "two hundred thirty-one million, two hundred fifteen thousand, two hundred forty".