231518640 has 40 divisors (see below), whose sum is σ = 717708528. Its totient is φ = 61738240.

The previous prime is 231518627. The next prime is 231518653. The reversal of 231518640 is 46815132.

231518640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (231518627) and next prime (231518653).

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 231518598 and 231518607.

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, 482091 + ... + 482570.

Almost surely, 2^231518640 is an apocalyptic number.

231518640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

231518640 is an abundant number, since it is smaller than the sum of its proper divisors (486189888).

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

231518640 is a wasteful number, since it uses less digits than its factorization.

231518640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 964677 (or 964671 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 231518640 is about 15215.7365907800. The cubic root of 231518640 is about 614.0381023722.

The spelling of 231518640 in words is "two hundred thirty-one million, five hundred eighteen thousand, six hundred forty".