639662042 has 16 divisors (see below), whose sum is σ = 968760000. Its totient is φ = 316753248.

The previous prime is 639662017. The next prime is 639662069. The reversal of 639662042 is 240266936.

639662042 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 639661987 and 639662005.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 125459 + ... + 130457.

It is an arithmetic number, because the mean of its divisors is an integer number (60547500).

Almost surely, 2^639662042 is an apocalyptic number.

639662042 is a deficient number, since it is larger than the sum of its proper divisors (329097958).

639662042 is a wasteful number, since it uses less digits than its factorization.

639662042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5605.

The product of its (nonzero) digits is 93312, while the sum is 38.

The square root of 639662042 is about 25291.5409178642. The cubic root of 639662042 is about 861.6221600465.

The spelling of 639662042 in words is "six hundred thirty-nine million, six hundred sixty-two thousand, forty-two".