639403434 has 24 divisors (see below), whose sum is σ = 1386004932. Its totient is φ = 213037440.

The previous prime is 639403411. The next prime is 639403441. The reversal of 639403434 is 434304936.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 573842025 + 65561409 = 23955^2 + 8097^2 .

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 40402 + ... + 53954.

Almost surely, 2^639403434 is an apocalyptic number.

639403434 is an abundant number, since it is smaller than the sum of its proper divisors (746601498).

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

639403434 is a wasteful number, since it uses less digits than its factorization.

639403434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16182 (or 16179 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 36.

The square root of 639403434 is about 25286.4278616020. The cubic root of 639403434 is about 861.5060297548.

The spelling of 639403434 in words is "six hundred thirty-nine million, four hundred three thousand, four hundred thirty-four".