138878099 has 4 divisors (see below), whose sum is σ = 140152320. Its totient is φ = 137603880.

The previous prime is 138878063. The next prime is 138878137. The reversal of 138878099 is 990878831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 990878831 = 53 ⋅18695827.

It is a cyclic number.

It is not a de Polignac number, because 138878099 - 2¹⁶ = 138812563 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 138878099.

It is not an unprimeable number, because it can be changed into a prime (138878009) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 636947 + ... + 637164.

It is an arithmetic number, because the mean of its divisors is an integer number (35038080).

Almost surely, 2^138878099 is an apocalyptic number.

138878099 is a deficient number, since it is larger than the sum of its proper divisors (1274221).

138878099 is a wasteful number, since it uses less digits than its factorization.

138878099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1274220.

The product of its (nonzero) digits is 870912, while the sum is 53.

The square root of 138878099 is about 11784.6552346685. The cubic root of 138878099 is about 517.8586733010.

The spelling of 138878099 in words is "one hundred thirty-eight million, eight hundred seventy-eight thousand, ninety-nine".