138220916 has 24 divisors (see below), whose sum is σ = 246261960. Its totient is φ = 67871232.

The previous prime is 138220891. The next prime is 138220939. The reversal of 138220916 is 619022831.

It can be written as a sum of positive squares in 4 ways, for example, as 8352100 + 129868816 = 2890^2 + 11396^2 .

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 54656 + ... + 57128.

It is an arithmetic number, because the mean of its divisors is an integer number (10260915).

Almost surely, 2^138220916 is an apocalyptic number.

It is an amenable number.

138220916 is a deficient number, since it is larger than the sum of its proper divisors (108041044).

138220916 is a wasteful number, since it uses less digits than its factorization.

138220916 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2723 (or 2721 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 138220916 is about 11756.7391737675. The cubic root of 138220916 is about 517.0405309759.

The spelling of 138220916 in words is "one hundred thirty-eight million, two hundred twenty thousand, nine hundred sixteen".