639382890 has 16 divisors (see below), whose sum is σ = 1534519008. Its totient is φ = 170502096.

The previous prime is 639382883. The next prime is 639382921. The reversal of 639382890 is 98283936.

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, 10656352 + ... + 10656411.

It is an arithmetic number, because the mean of its divisors is an integer number (95907438).

Almost surely, 2^639382890 is an apocalyptic number.

639382890 is an abundant number, since it is smaller than the sum of its proper divisors (895136118).

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

639382890 is a wasteful number, since it uses less digits than its factorization.

639382890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21312773.

The product of its (nonzero) digits is 559872, while the sum is 48.

The square root of 639382890 is about 25286.0216325147. The cubic root of 639382890 is about 861.4968029410.

The spelling of 639382890 in words is "six hundred thirty-nine million, three hundred eighty-two thousand, eight hundred ninety".