138638115 has 64 divisors (see below), whose sum is σ = 307307520. Its totient is φ = 57611520.

The previous prime is 138638113. The next prime is 138638119. The reversal of 138638115 is 511836831.

138638115 is a `hidden beast` number, since 1 + 3 + 8 + 638 + 1 + 15 = 666.

It is not a de Polignac number, because 138638115 - 2¹ = 138638113 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 138638115.

It is not an unprimeable number, because it can be changed into a prime (138638113) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3727 + ... + 17063.

It is an arithmetic number, because the mean of its divisors is an integer number (4801680).

Almost surely, 2^138638115 is an apocalyptic number.

138638115 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

138638115 is an abundant number, since it is smaller than the sum of its proper divisors (168669405).

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

138638115 is a wasteful number, since it uses less digits than its factorization.

138638115 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13369 (or 13363 counting only the distinct ones).

The product of its digits is 17280, while the sum is 36.

The square root of 138638115 is about 11774.4687778260. The cubic root of 138638115 is about 517.5602114356.

The spelling of 138638115 in words is "one hundred thirty-eight million, six hundred thirty-eight thousand, one hundred fifteen".