640713205204 has 6 divisors (see below), whose sum is σ = 1121248109114. Its totient is φ = 320356602600.

The previous prime is 640713205183. The next prime is 640713205213. The reversal of 640713205204 is 402502317046.

It can be written as a sum of positive squares in only one way, i.e., 636960417604 + 3752787600 = 798098^2 + 61260^2 .

It is a super-2 number, since 2×640713205204² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 640713205204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80089150647 + ... + 80089150654.

Almost surely, 2^640713205204 is an apocalyptic number.

It is an amenable number.

640713205204 is a deficient number, since it is larger than the sum of its proper divisors (480534903910).

640713205204 is a wasteful number, since it uses less digits than its factorization.

640713205204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160178301305 (or 160178301303 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 34.

The spelling of 640713205204 in words is "six hundred forty billion, seven hundred thirteen million, two hundred five thousand, two hundred four".