640140368 has 40 divisors (see below), whose sum is σ = 1419075840. Its totient is φ = 274032000.

The previous prime is 640140353. The next prime is 640140373. The reversal of 640140368 is 863041046.

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, 113618 + ... + 119118.

It is an arithmetic number, because the mean of its divisors is an integer number (35476896).

Almost surely, 2^640140368 is an apocalyptic number.

It is an amenable number.

640140368 is an abundant number, since it is smaller than the sum of its proper divisors (778935472).

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

640140368 is a wasteful number, since it uses less digits than its factorization.

640140368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6555 (or 6549 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 32.

The square root of 640140368 is about 25300.9953954385. The cubic root of 640140368 is about 861.8368742591.

The spelling of 640140368 in words is "six hundred forty million, one hundred forty thousand, three hundred sixty-eight".