638861713538 has 8 divisors (see below), whose sum is σ = 958295979840. Its totient is φ = 319429720260.

The previous prime is 638861713537. The next prime is 638861713559. The reversal of 638861713538 is 835317168836.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (638861713537) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 704843 + ... + 1332113.

It is an arithmetic number, because the mean of its divisors is an integer number (119786997480).

Almost surely, 2^638861713538 is an apocalyptic number.

638861713538 is a deficient number, since it is larger than the sum of its proper divisors (319434266302).

638861713538 is a wasteful number, since it uses less digits than its factorization.

638861713538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1136512.

The product of its digits is 17418240, while the sum is 59.

The spelling of 638861713538 in words is "six hundred thirty-eight billion, eight hundred sixty-one million, seven hundred thirteen thousand, five hundred thirty-eight".