639492386 has 64 divisors (see below), whose sum is σ = 1137628800. Its totient is φ = 266996736.

The previous prime is 639492379. The next prime is 639492401. The reversal of 639492386 is 683294936.

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 31 ways as a sum of consecutive naturals, for example, 1078106 + ... + 1078698.

It is an arithmetic number, because the mean of its divisors is an integer number (17775450).

Almost surely, 2^639492386 is an apocalyptic number.

639492386 is a deficient number, since it is larger than the sum of its proper divisors (498136414).

639492386 is a wasteful number, since it uses less digits than its factorization.

639492386 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 723.

The product of its digits is 1679616, while the sum is 50.

The square root of 639492386 is about 25288.1866886497. The cubic root of 639492386 is about 861.5459779977.

The spelling of 639492386 in words is "six hundred thirty-nine million, four hundred ninety-two thousand, three hundred eighty-six".