640066932 has 72 divisors (see below), whose sum is σ = 1716938496. Its totient is φ = 200358144.

The previous prime is 640066913. The next prime is 640066943. The reversal of 640066932 is 239660046.

640066932 is a `hidden beast` number, since 640 + 0 + 6 + 6 + 9 + 3 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

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, 370623 + ... + 372345.

It is an arithmetic number, because the mean of its divisors is an integer number (23846368).

Almost surely, 2^640066932 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640066932, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (858469248).

640066932 is an abundant number, since it is smaller than the sum of its proper divisors (1076871564).

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

640066932 is a wasteful number, since it uses less digits than its factorization.

640066932 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2357 (or 2352 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 36.

The square root of 640066932 is about 25299.5441065645. The cubic root of 640066932 is about 861.8039167619.

The spelling of 640066932 in words is "six hundred forty million, sixty-six thousand, nine hundred thirty-two".