138877920 has 72 divisors (see below), whose sum is σ = 473925816. Its totient is φ = 37033728.

The previous prime is 138877883. The next prime is 138877927. The reversal of 138877920 is 29778831.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138877927) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 46782 + ... + 49661.

It is an arithmetic number, because the mean of its divisors is an integer number (6582303).

Almost surely, 2^138877920 is an apocalyptic number.

138877920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138877920 is an abundant number, since it is smaller than the sum of its proper divisors (335047896).

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

138877920 is a wasteful number, since it uses less digits than its factorization.

138877920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96464 (or 96453 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 45.

The square root of 138877920 is about 11784.6476400442. The cubic root of 138877920 is about 517.8584508115.

The spelling of 138877920 in words is "one hundred thirty-eight million, eight hundred seventy-seven thousand, nine hundred twenty".