138879872 has 64 divisors (see below), whose sum is σ = 285314400. Its totient is φ = 67313664.

The previous prime is 138879863. The next prime is 138879929. The reversal of 138879872 is 278978831.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 831533 + ... + 831699.

Almost surely, 2^138879872 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138879872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (142657200).

138879872 is an abundant number, since it is smaller than the sum of its proper divisors (146434528).

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

138879872 is an equidigital number, since it uses as much as digits as its factorization.

138879872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 343 (or 331 counting only the distinct ones).

The product of its digits is 1354752, while the sum is 53.

The square root of 138879872 is about 11784.7304593699. The cubic root of 138879872 is about 517.8608770550.

The spelling of 138879872 in words is "one hundred thirty-eight million, eight hundred seventy-nine thousand, eight hundred seventy-two".