138731418 has 48 divisors (see below), whose sum is σ = 355380480. Its totient is φ = 38269728.

The previous prime is 138731393. The next prime is 138731431. The reversal of 138731418 is 814137831.

138731418 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15330 + ... + 22637.

It is an arithmetic number, because the mean of its divisors is an integer number (7403760).

Almost surely, 2^138731418 is an apocalyptic number.

138731418 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

138731418 is an abundant number, since it is smaller than the sum of its proper divisors (216649062).

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

138731418 is a wasteful number, since it uses less digits than its factorization.

138731418 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38011 (or 38008 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 138731418 is about 11778.4302010073. The cubic root of 138731418 is about 517.6762908449.

The spelling of 138731418 in words is "one hundred thirty-eight million, seven hundred thirty-one thousand, four hundred eighteen".