138871968 has 48 divisors (see below), whose sum is σ = 367234560. Its totient is φ = 45948416.

The previous prime is 138871949. The next prime is 138871973. The reversal of 138871968 is 869178831.

It is a tau number, because it is divible by the number of its divisors (48).

It is a self number, because there is not a number n which added to its sum of digits gives 138871968.

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, 7873 + ... + 18431.

It is an arithmetic number, because the mean of its divisors is an integer number (7650720).

Almost surely, 2^138871968 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 138871968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (183617280).

138871968 is an abundant number, since it is smaller than the sum of its proper divisors (228362592).

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

138871968 is a wasteful number, since it uses less digits than its factorization.

138871968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10709 (or 10701 counting only the distinct ones).

The product of its digits is 580608, while the sum is 51.

The square root of 138871968 is about 11784.3951053926. The cubic root of 138871968 is about 517.8510526171.

The spelling of 138871968 in words is "one hundred thirty-eight million, eight hundred seventy-one thousand, nine hundred sixty-eight".