138878436 has 12 divisors (see below), whose sum is σ = 324049712. Its totient is φ = 46292808.

The previous prime is 138878417. The next prime is 138878447. The reversal of 138878436 is 634878831.

It is a tau number, because it is divible by the number of its divisors (12).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5786590 + ... + 5786613.

Almost surely, 2^138878436 is an apocalyptic number.

It is an amenable number.

138878436 is an abundant number, since it is smaller than the sum of its proper divisors (185171276).

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

138878436 is a wasteful number, since it uses less digits than its factorization.

138878436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11573210 (or 11573208 counting only the distinct ones).

The product of its digits is 774144, while the sum is 48.

The square root of 138878436 is about 11784.6695329144. The cubic root of 138878436 is about 517.8590921772.

The spelling of 138878436 in words is "one hundred thirty-eight million, eight hundred seventy-eight thousand, four hundred thirty-six".