638597685 has 32 divisors (see below), whose sum is σ = 1128775680. Its totient is φ = 305697600.

The previous prime is 638597677. The next prime is 638597699. The reversal of 638597685 is 586795836.

It is not a de Polignac number, because 638597685 - 2³ = 638597677 is a prime.

It is a Smith number, since the sum of its digits (57) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11461 + ... + 37530.

It is an arithmetic number, because the mean of its divisors is an integer number (35274240).

Almost surely, 2^638597685 is an apocalyptic number.

It is an amenable number.

638597685 is a deficient number, since it is larger than the sum of its proper divisors (490177995).

638597685 is a wasteful number, since it uses less digits than its factorization.

638597685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49089.

The product of its digits is 10886400, while the sum is 57.

The square root of 638597685 is about 25270.4903988823. The cubic root of 638597685 is about 861.1439998939.

The spelling of 638597685 in words is "six hundred thirty-eight million, five hundred ninety-seven thousand, six hundred eighty-five".