138078615 has 16 divisors (see below), whose sum is σ = 223115616. Its totient is φ = 72912000.

The previous prime is 138078613. The next prime is 138078667. The reversal of 138078615 is 516870831.

It is not a de Polignac number, because 138078615 - 2¹ = 138078613 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138078613) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 44056 + ... + 47085.

It is an arithmetic number, because the mean of its divisors is an integer number (13944726).

Almost surely, 2^138078615 is an apocalyptic number.

138078615 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

138078615 is a deficient number, since it is larger than the sum of its proper divisors (85037001).

138078615 is a wasteful number, since it uses less digits than its factorization.

138078615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91250.

The product of its (nonzero) digits is 40320, while the sum is 39.

The square root of 138078615 is about 11750.6857246716. The cubic root of 138078615 is about 516.8630357741.

It can be divided in two parts, 13807 and 8615, that added together give a palindrome (22422).

The spelling of 138078615 in words is "one hundred thirty-eight million, seventy-eight thousand, six hundred fifteen".