138515816 has 8 divisors (see below), whose sum is σ = 259717170. Its totient is φ = 69257904.

The previous prime is 138515801. The next prime is 138515837. The reversal of 138515816 is 618515831.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 116856100 + 21659716 = 10810^2 + 4654^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 138515816.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8657231 + ... + 8657246.

Almost surely, 2^138515816 is an apocalyptic number.

It is an amenable number.

138515816 is a deficient number, since it is larger than the sum of its proper divisors (121201354).

138515816 is a wasteful number, since it uses less digits than its factorization.

138515816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17314483 (or 17314479 counting only the distinct ones).

The product of its digits is 28800, while the sum is 38.

The square root of 138515816 is about 11769.2742342083. The cubic root of 138515816 is about 517.4079788459.

The spelling of 138515816 in words is "one hundred thirty-eight million, five hundred fifteen thousand, eight hundred sixteen".