138520920 has 64 divisors (see below), whose sum is σ = 416586240. Its totient is φ = 36848000.

The previous prime is 138520909. The next prime is 138520939. The reversal of 138520920 is 29025831.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

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, 57745 + ... + 60095.

It is an arithmetic number, because the mean of its divisors is an integer number (6509160).

Almost surely, 2^138520920 is an apocalyptic number.

138520920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138520920 is an abundant number, since it is smaller than the sum of its proper divisors (278065320).

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

138520920 is a wasteful number, since it uses less digits than its factorization.

138520920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2856 (or 2852 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 138520920 is about 11769.4910680114. The cubic root of 138520920 is about 517.4143338792.

The spelling of 138520920 in words is "one hundred thirty-eight million, five hundred twenty thousand, nine hundred twenty".