640704516 has 12 divisors (see below), whose sum is σ = 1494977232. Its totient is φ = 213568168.

The previous prime is 640704481. The next prime is 640704553. The reversal of 640704516 is 615407046.

It is a tau number, because it is divible by the number of its divisors (12).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26696010 + ... + 26696033.

It is an arithmetic number, because the mean of its divisors is an integer number (124581436).

Almost surely, 2^640704516 is an apocalyptic number.

It is an amenable number.

640704516 is an abundant number, since it is smaller than the sum of its proper divisors (854272716).

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

640704516 is a wasteful number, since it uses less digits than its factorization.

640704516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53392050 (or 53392048 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 33.

The square root of 640704516 is about 25312.1416715378. The cubic root of 640704516 is about 862.0899754093.

It can be divided in two parts, 64070 and 4516, that added together give a palindrome (68586).

The spelling of 640704516 in words is "six hundred forty million, seven hundred four thousand, five hundred sixteen".