138555988 has 24 divisors (see below), whose sum is σ = 250838784. Its totient is φ = 66897600.

The previous prime is 138555983. The next prime is 138556021. The reversal of 138555988 is 889555831.

It is a super-2 number, since 2×138555988² = 38395523621312288, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138555983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 75603 + ... + 77413.

It is an arithmetic number, because the mean of its divisors is an integer number (10451616).

Almost surely, 2^138555988 is an apocalyptic number.

It is an amenable number.

138555988 is a deficient number, since it is larger than the sum of its proper divisors (112282796).

138555988 is a wasteful number, since it uses less digits than its factorization.

138555988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2463 (or 2461 counting only the distinct ones).

The product of its digits is 1728000, while the sum is 52.

The square root of 138555988 is about 11770.9807577789. The cubic root of 138555988 is about 517.4579931207.

The spelling of 138555988 in words is "one hundred thirty-eight million, five hundred fifty-five thousand, nine hundred eighty-eight".