638984805 has 16 divisors (see below), whose sum is σ = 1025649600. Its totient is φ = 339700608.

The previous prime is 638984791. The next prime is 638984813. The reversal of 638984805 is 508489836.

It is not a de Polignac number, because 638984805 - 2⁴ = 638984789 is a prime.

It is a congruent number.

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, 63355 + ... + 72744.

It is an arithmetic number, because the mean of its divisors is an integer number (64103100).

Almost surely, 2^638984805 is an apocalyptic number.

It is an amenable number.

638984805 is a deficient number, since it is larger than the sum of its proper divisors (386664795).

638984805 is a wasteful number, since it uses less digits than its factorization.

638984805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136420.

The product of its (nonzero) digits is 1658880, while the sum is 51.

The square root of 638984805 is about 25278.1487652874. The cubic root of 638984805 is about 861.3179741781.

The spelling of 638984805 in words is "six hundred thirty-eight million, nine hundred eighty-four thousand, eight hundred five".