639477385 has 16 divisors (see below), whose sum is σ = 780595200. Its totient is φ = 502842816.

The previous prime is 639477379. The next prime is 639477403. The reversal of 639477385 is 583774936.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 639477385 - 2¹¹ = 639475337 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 64596 + ... + 73834.

It is an arithmetic number, because the mean of its divisors is an integer number (48787200).

Almost surely, 2^639477385 is an apocalyptic number.

It is an amenable number.

639477385 is a deficient number, since it is larger than the sum of its proper divisors (141117815).

639477385 is a wasteful number, since it uses less digits than its factorization.

639477385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9480.

The product of its digits is 3810240, while the sum is 52.

The square root of 639477385 is about 25287.8900859680. The cubic root of 639477385 is about 861.5392413252.

The spelling of 639477385 in words is "six hundred thirty-nine million, four hundred seventy-seven thousand, three hundred eighty-five".