638927099878 has 8 divisors (see below), whose sum is σ = 969937525368. Its totient is φ = 315614591424.

The previous prime is 638927099873. The next prime is 638927099939. The reversal of 638927099878 is 878990729836.

638927099878 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a super-2 number, since 2×638927099878² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638927099873) 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, 1924479051 + ... + 1924479382.

It is an arithmetic number, because the mean of its divisors is an integer number (121242190671).

Almost surely, 2^638927099878 is an apocalyptic number.

638927099878 is a deficient number, since it is larger than the sum of its proper divisors (331010425490).

638927099878 is a wasteful number, since it uses less digits than its factorization.

638927099878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3848958518.

The product of its (nonzero) digits is 658409472, while the sum is 76.

The spelling of 638927099878 in words is "six hundred thirty-eight billion, nine hundred twenty-seven million, ninety-nine thousand, eight hundred seventy-eight".