640464100 has 36 divisors (see below), whose sum is σ = 1391254704. Its totient is φ = 255918880.

The previous prime is 640464079. The next prime is 640464107. The reversal of 640464100 is 1464046.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (640464107) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 113547 + ... + 119053.

It is an arithmetic number, because the mean of its divisors is an integer number (38645964).

Almost surely, 2^640464100 is an apocalyptic number.

It is an amenable number.

640464100 is an abundant number, since it is smaller than the sum of its proper divisors (750790604).

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

640464100 is a wasteful number, since it uses less digits than its factorization.

640464100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6684 (or 6677 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 640464100 is about 25307.3922006990. The cubic root of 640464100 is about 861.9821325854.

The spelling of 640464100 in words is "six hundred forty million, four hundred sixty-four thousand, one hundred".