634686138 has 32 divisors (see below), whose sum is σ = 1418587200. Its totient is φ = 210336048.

The previous prime is 634686133. The next prime is 634686139. The reversal of 634686138 is 831686436.

634686138 is a `hidden beast` number, since 634 + 6 + 8 + 6 + 1 + 3 + 8 = 666.

634686138 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 634686093 and 634686102.

It is not an unprimeable number, because it can be changed into a prime (634686133) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24628 + ... + 43311.

It is an arithmetic number, because the mean of its divisors is an integer number (44330850).

Almost surely, 2^634686138 is an apocalyptic number.

634686138 is an abundant number, since it is smaller than the sum of its proper divisors (783901062).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

634686138 is a wasteful number, since it uses less digits than its factorization.

634686138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68123 (or 68117 counting only the distinct ones).

The product of its digits is 497664, while the sum is 45.

The square root of 634686138 is about 25192.9779502146. The cubic root of 634686138 is about 859.3821675709.

The spelling of 634686138 in words is "six hundred thirty-four million, six hundred eighty-six thousand, one hundred thirty-eight".