78872352138 has 12 divisors (see below), whose sum is σ = 170890096338. Its totient is φ = 26290784040.

The previous prime is 78872352137. The next prime is 78872352157. The reversal of 78872352138 is 83125327887.

78872352138 is a `hidden beast` number, since 7 + 8 + 87 + 2 + 3 + 521 + 38 = 666.

It can be written as a sum of positive squares in only one way, i.e., 68778734049 + 10093618089 = 262257^2 + 100467^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (78872352137) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2190898653 + ... + 2190898688.

Almost surely, 2^78872352138 is an apocalyptic number.

78872352138 is an abundant number, since it is smaller than the sum of its proper divisors (92017744200).

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

78872352138 is a wasteful number, since it uses less digits than its factorization.

78872352138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4381797349 (or 4381797346 counting only the distinct ones).

The product of its digits is 4515840, while the sum is 54.

The spelling of 78872352138 in words is "seventy-eight billion, eight hundred seventy-two million, three hundred fifty-two thousand, one hundred thirty-eight".