639647344475 has 6 divisors (see below), whose sum is σ = 793162707180. Its totient is φ = 511717875560.

The previous prime is 639647344459. The next prime is 639647344529. The reversal of 639647344475 is 574443746936.

It is not a de Polignac number, because 639647344475 - 2⁴ = 639647344459 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12792946865 + ... + 12792946914.

It is an arithmetic number, because the mean of its divisors is an integer number (132193784530).

Almost surely, 2^639647344475 is an apocalyptic number.

639647344475 is a deficient number, since it is larger than the sum of its proper divisors (153515362705).

639647344475 is a wasteful number, since it uses less digits than its factorization.

639647344475 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25585893789 (or 25585893784 counting only the distinct ones).

The product of its digits is 182891520, while the sum is 62.

The spelling of 639647344475 in words is "six hundred thirty-nine billion, six hundred forty-seven million, three hundred forty-four thousand, four hundred seventy-five".