640446402 has 16 divisors (see below), whose sum is σ = 1289491200. Its totient is φ = 212049072.

The previous prime is 640446349. The next prime is 640446413. The reversal of 640446402 is 204644046.

640446402 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 640446402.

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, 357298 + ... + 359085.

It is an arithmetic number, because the mean of its divisors is an integer number (80593200).

Almost surely, 2^640446402 is an apocalyptic number.

640446402 is an abundant number, since it is smaller than the sum of its proper divisors (649044798).

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

640446402 is a wasteful number, since it uses less digits than its factorization.

640446402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 716537.

The product of its (nonzero) digits is 18432, while the sum is 30.

The square root of 640446402 is about 25307.0425376021. The cubic root of 640446402 is about 861.9741927700.

The spelling of 640446402 in words is "six hundred forty million, four hundred forty-six thousand, four hundred two".