138218615 has 32 divisors (see below), whose sum is σ = 180596736. Its totient is φ = 101249280.

The previous prime is 138218579. The next prime is 138218617. The reversal of 138218615 is 516812831.

138218615 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 138218615 - 2¹⁸ = 137956471 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138218617) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 488264 + ... + 488546.

It is an arithmetic number, because the mean of its divisors is an integer number (5643648).

Almost surely, 2^138218615 is an apocalyptic number.

138218615 is a deficient number, since it is larger than the sum of its proper divisors (42378121).

138218615 is a wasteful number, since it uses less digits than its factorization.

138218615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 479.

The product of its digits is 11520, while the sum is 35.

The square root of 138218615 is about 11756.6413145932. The cubic root of 138218615 is about 517.0376618566.

The spelling of 138218615 in words is "one hundred thirty-eight million, two hundred eighteen thousand, six hundred fifteen".