639798634 has 16 divisors (see below), whose sum is σ = 987715872. Its totient is φ = 310646448.

The previous prime is 639798589. The next prime is 639798637. The reversal of 639798634 is 436897936.

It is a super-4 number, since 4×639798634⁴ (a number of 36 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (639798637) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 6624 + ... + 36379.

It is an arithmetic number, because the mean of its divisors is an integer number (61732242).

Almost surely, 2^639798634 is an apocalyptic number.

639798634 is a deficient number, since it is larger than the sum of its proper divisors (347917238).

639798634 is a wasteful number, since it uses less digits than its factorization.

639798634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43221.

The product of its digits is 5878656, while the sum is 55.

The square root of 639798634 is about 25294.2411232280. The cubic root of 639798634 is about 861.6834853038.

The spelling of 639798634 in words is "six hundred thirty-nine million, seven hundred ninety-eight thousand, six hundred thirty-four".