138629864 has 8 divisors (see below), whose sum is σ = 259931010. Its totient is φ = 69314928.

The previous prime is 138629851. The next prime is 138629879. The reversal of 138629864 is 468926831.

138629864 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 131285764 + 7344100 = 11458^2 + 2710^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8664359 + ... + 8664374.

Almost surely, 2^138629864 is an apocalyptic number.

It is an amenable number.

138629864 is a deficient number, since it is larger than the sum of its proper divisors (121301146).

138629864 is a wasteful number, since it uses less digits than its factorization.

138629864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17328739 (or 17328735 counting only the distinct ones).

The product of its digits is 497664, while the sum is 47.

The square root of 138629864 is about 11774.1183958715. The cubic root of 138629864 is about 517.5499437589.

The spelling of 138629864 in words is "one hundred thirty-eight million, six hundred twenty-nine thousand, eight hundred sixty-four".