639372405 has 16 divisors (see below), whose sum is σ = 1169138304. Its totient is φ = 292284480.

The previous prime is 639372373. The next prime is 639372407. The reversal of 639372405 is 504273936.

It is not a de Polignac number, because 639372405 - 2⁵ = 639372373 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639372407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3044526 + ... + 3044735.

It is an arithmetic number, because the mean of its divisors is an integer number (73071144).

Almost surely, 2^639372405 is an apocalyptic number.

It is an amenable number.

639372405 is a deficient number, since it is larger than the sum of its proper divisors (529765899).

639372405 is a wasteful number, since it uses less digits than its factorization.

639372405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6089276.

The product of its (nonzero) digits is 136080, while the sum is 39.

The square root of 639372405 is about 25285.8143036763. The cubic root of 639372405 is about 861.4920937943.

The spelling of 639372405 in words is "six hundred thirty-nine million, three hundred seventy-two thousand, four hundred five".