231331240 has 128 divisors (see below), whose sum is σ = 657538560. Its totient is φ = 71368704.

The previous prime is 231331237. The next prime is 231331249. The reversal of 231331240 is 42133132.

231331240 = 70² + 71² + ... + 885².

It is not an unprimeable number, because it can be changed into a prime (231331249) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 108424 + ... + 110536.

It is an arithmetic number, because the mean of its divisors is an integer number (5137020).

Almost surely, 2^231331240 is an apocalyptic number.

231331240 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 231331240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (328769280).

231331240 is an abundant number, since it is smaller than the sum of its proper divisors (426207320).

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

231331240 is a wasteful number, since it uses less digits than its factorization.

231331240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2171 (or 2167 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 19.

The square root of 231331240 is about 15209.5772459329. The cubic root of 231331240 is about 613.8723823796.

Adding to 231331240 its reverse (42133132), we get a palindrome (273464372).

The spelling of 231331240 in words is "two hundred thirty-one million, three hundred thirty-one thousand, two hundred forty".