640066600 has 24 divisors (see below), whose sum is σ = 1488155310. Its totient is φ = 256026560.

The previous prime is 640066573. The next prime is 640066613. The reversal of 640066600 is 6660046.

It can be written as a sum of positive squares in 3 ways, for example, as 508322116 + 131744484 = 22546^2 + 11478^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1599967 + ... + 1600366.

Almost surely, 2^640066600 is an apocalyptic number.

It is an amenable number.

640066600 is an abundant number, since it is smaller than the sum of its proper divisors (848088710).

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

640066600 is a wasteful number, since it uses less digits than its factorization.

640066600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3200349 (or 3200340 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 28.

The square root of 640066600 is about 25299.5375451805. The cubic root of 640066600 is about 861.8037677572.

The spelling of 640066600 in words is "six hundred forty million, sixty-six thousand, six hundred".