138121896 has 64 divisors (see below), whose sum is σ = 389707200. Its totient is φ = 40409600.

The previous prime is 138121883. The next prime is 138121903. The reversal of 138121896 is 698121831.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1365 + ... + 16676.

It is an arithmetic number, because the mean of its divisors is an integer number (6089175).

Almost surely, 2^138121896 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 138121896, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (194853600).

138121896 is an abundant number, since it is smaller than the sum of its proper divisors (251585304).

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

138121896 is a wasteful number, since it uses less digits than its factorization.

138121896 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18090 (or 18086 counting only the distinct ones).

The product of its digits is 20736, while the sum is 39.

The square root of 138121896 is about 11752.5272175818. The cubic root of 138121896 is about 516.9170340275.

The spelling of 138121896 in words is "one hundred thirty-eight million, one hundred twenty-one thousand, eight hundred ninety-six".