640662900 has 72 divisors (see below), whose sum is σ = 1951229280. Its totient is φ = 161850240.

The previous prime is 640662889. The next prime is 640662923. The reversal of 640662900 is 9266046.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 50499 + ... + 61898.

Almost surely, 2^640662900 is an apocalyptic number.

640662900 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

640662900 is an abundant number, since it is smaller than the sum of its proper divisors (1310566380).

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

640662900 is a wasteful number, since it uses less digits than its factorization.

640662900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112433 (or 112426 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 33.

The square root of 640662900 is about 25311.3196021069. The cubic root of 640662900 is about 862.0713097518.

It can be divided in two parts, 64066 and 2900, that added together give a palindrome (66966).

The spelling of 640662900 in words is "six hundred forty million, six hundred sixty-two thousand, nine hundred".