138813855 has 16 divisors (see below), whose sum is σ = 231759360. Its totient is φ = 70815008.

The previous prime is 138813839. The next prime is 138813881. The reversal of 138813855 is 558318831.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 138813855 - 2⁴ = 138813839 is a prime.

It is a super-2 number, since 2×138813855² = 38538572679922050, which contains 22 as substring.

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, 200835 + ... + 201524.

It is an arithmetic number, because the mean of its divisors is an integer number (14484960).

Almost surely, 2^138813855 is an apocalyptic number.

138813855 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

138813855 is a deficient number, since it is larger than the sum of its proper divisors (92945505).

138813855 is a wasteful number, since it uses less digits than its factorization.

138813855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 402390.

The product of its digits is 115200, while the sum is 42.

The square root of 138813855 is about 11781.9291714048. The cubic root of 138813855 is about 517.7788084309.

The spelling of 138813855 in words is "one hundred thirty-eight million, eight hundred thirteen thousand, eight hundred fifty-five".