79906605138 has 24 divisors (see below), whose sum is σ = 179543237328. Its totient is φ = 26635534884.

The previous prime is 79906605131. The next prime is 79906605199. The reversal of 79906605138 is 83150660997.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (79906605131) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 82207956 + ... + 82208927.

It is an arithmetic number, because the mean of its divisors is an integer number (7480968222).

Almost surely, 2^79906605138 is an apocalyptic number.

79906605138 is an abundant number, since it is smaller than the sum of its proper divisors (99636632190).

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

79906605138 is a wasteful number, since it uses less digits than its factorization.

79906605138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164416900 (or 164416888 counting only the distinct ones).

The product of its (nonzero) digits is 2449440, while the sum is 54.

The spelling of 79906605138 in words is "seventy-nine billion, nine hundred six million, six hundred five thousand, one hundred thirty-eight".