639593664516 has 81 divisors (see below), whose sum is σ = 1657655264629. Its totient is φ = 207933960000.

The previous prime is 639593664511. The next prime is 639593664559. The reversal of 639593664516 is 615466395936.

It is a happy number.

The square root of 639593664516 is 799746.

It is a perfect power (a square), and thus also a powerful number.

639593664516 is a `hidden beast` number, since 6 + 3 + 9 + 59 + 3 + 6 + 64 + 516 = 666.

It can be written as a sum of positive squares in only one way, i.e., 30819206916 + 608774457600 = 175554^2 + 780240^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (639593664511) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 196735891 + ... + 196739141.

Almost surely, 2^639593664516 is an apocalyptic number.

639593664516 is the 799746-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639593664516

639593664516 is an abundant number, since it is smaller than the sum of its proper divisors (1018061600113).

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

639593664516 is an equidigital number, since it uses as much as digits as its factorization.

639593664516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6594 (or 3297 counting only the distinct ones).

The product of its digits is 94478400, while the sum is 63.

The spelling of 639593664516 in words is "six hundred thirty-nine billion, five hundred ninety-three million, six hundred sixty-four thousand, five hundred sixteen".