231287640 has 32 divisors (see below), whose sum is σ = 693863280. Its totient is φ = 61676672.

The previous prime is 231287603. The next prime is 231287659. The reversal of 231287640 is 46782132.

231287640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

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, 963579 + ... + 963818.

Almost surely, 2^231287640 is an apocalyptic number.

231287640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

231287640 is an abundant number, since it is smaller than the sum of its proper divisors (462575640).

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

231287640 is a wasteful number, since it uses less digits than its factorization.

231287640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1927411 (or 1927407 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 33.

The square root of 231287640 is about 15208.1438709660. The cubic root of 231287640 is about 613.8338135616.

The spelling of 231287640 in words is "two hundred thirty-one million, two hundred eighty-seven thousand, six hundred forty".