79138813 has 6 divisors (see below), whose sum is σ = 85694874. Its totient is φ = 73051056.

The previous prime is 79138799. The next prime is 79138823. The reversal of 79138813 is 31883197.

It can be written as a sum of positive squares in 3 ways, for example, as 7601049 + 71537764 = 2757^2 + 8458^2 .

It is a de Polignac number, because none of the positive numbers 2^k-79138813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79138823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 233970 + ... + 234307.

It is an arithmetic number, because the mean of its divisors is an integer number (14282479).

Almost surely, 2^79138813 is an apocalyptic number.

It is an amenable number.

79138813 is a deficient number, since it is larger than the sum of its proper divisors (6556061).

79138813 is a wasteful number, since it uses less digits than its factorization.

79138813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 468303 (or 468290 counting only the distinct ones).

The product of its digits is 36288, while the sum is 40.

The square root of 79138813 is about 8895.9998313849. Note that the first 3 decimals coincide. The cubic root of 79138813 is about 429.3352139726.

The spelling of 79138813 in words is "seventy-nine million, one hundred thirty-eight thousand, eight hundred thirteen".