639575145172 has 6 divisors (see below), whose sum is σ = 1119256504058. Its totient is φ = 319787572584.

The previous prime is 639575145169. The next prime is 639575145173. The reversal of 639575145172 is 271541575936.

639575145172 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 536345310736 + 103229834436 = 732356^2 + 321294^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639575145173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79946893143 + ... + 79946893150.

Almost surely, 2^639575145172 is an apocalyptic number.

It is an amenable number.

639575145172 is a deficient number, since it is larger than the sum of its proper divisors (479681358886).

639575145172 is a wasteful number, since it uses less digits than its factorization.

639575145172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159893786297 (or 159893786295 counting only the distinct ones).

The product of its digits is 7938000, while the sum is 55.

The spelling of 639575145172 in words is "six hundred thirty-nine billion, five hundred seventy-five million, one hundred forty-five thousand, one hundred seventy-two".