638870508885 has 64 divisors (see below), whose sum is σ = 1217943226368. Its totient is φ = 279880683264.

The previous prime is 638870508877. The next prime is 638870508923. The reversal of 638870508885 is 588805078836.

It is a happy number.

It is not a de Polignac number, because 638870508885 - 2³ = 638870508877 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1095607 + ... + 1574196.

It is an arithmetic number, because the mean of its divisors is an integer number (19030362912).

Almost surely, 2^638870508885 is an apocalyptic number.

It is an amenable number.

638870508885 is a deficient number, since it is larger than the sum of its proper divisors (579072717483).

638870508885 is a wasteful number, since it uses less digits than its factorization.

638870508885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2669914.

The product of its (nonzero) digits is 103219200, while the sum is 66.

The spelling of 638870508885 in words is "six hundred thirty-eight billion, eight hundred seventy million, five hundred eight thousand, eight hundred eighty-five".