639393946 has 16 divisors (see below), whose sum is σ = 971725824. Its totient is φ = 315512064.

The previous prime is 639393913. The next prime is 639393991. The reversal of 639393946 is 649393936.

It is a junction number, because it is equal to n+sod(n) for n = 639393893 and 639393902.

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, 42501 + ... + 55543.

It is an arithmetic number, because the mean of its divisors is an integer number (60732864).

Almost surely, 2^639393946 is an apocalyptic number.

639393946 is a deficient number, since it is larger than the sum of its proper divisors (332331878).

639393946 is a wasteful number, since it uses less digits than its factorization.

639393946 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13365.

The product of its digits is 2834352, while the sum is 52.

The square root of 639393946 is about 25286.2402503812. The cubic root of 639393946 is about 861.5017684861.

The spelling of 639393946 in words is "six hundred thirty-nine million, three hundred ninety-three thousand, nine hundred forty-six".