138145920 has 256 divisors, whose sum is σ = 498216960. Its totient is φ = 32256000.

The previous prime is 138145913. The next prime is 138145939. The reversal of 138145920 is 29541831.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 654615 + ... + 654825.

It is an arithmetic number, because the mean of its divisors is an integer number (1946160).

Almost surely, 2^138145920 is an apocalyptic number.

138145920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138145920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (249108480).

138145920 is an abundant number, since it is smaller than the sum of its proper divisors (360071040).

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

138145920 is a wasteful number, since it uses less digits than its factorization.

138145920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275 (or 263 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 33.

The square root of 138145920 is about 11753.5492511837. The cubic root of 138145920 is about 516.9470019888.

The spelling of 138145920 in words is "one hundred thirty-eight million, one hundred forty-five thousand, nine hundred twenty".