231131988 has 48 divisors (see below), whose sum is σ = 605436160. Its totient is φ = 76246272.

The previous prime is 231131987. The next prime is 231132019. The reversal of 231131988 is 889131132.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231131987) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 556 + ... + 21507.

Almost surely, 2^231131988 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 231131988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (302718080).

231131988 is an abundant number, since it is smaller than the sum of its proper divisors (374304172).

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

231131988 is a wasteful number, since it uses less digits than its factorization.

231131988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22173 (or 22165 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 231131988 is about 15203.0256199218. The cubic root of 231131988 is about 613.6960833281.

The spelling of 231131988 in words is "two hundred thirty-one million, one hundred thirty-one thousand, nine hundred eighty-eight".