79128173 has 2 divisors, whose sum is σ = 79128174. Its totient is φ = 79128172.

The previous prime is 79128169. The next prime is 79128191. The reversal of 79128173 is 37182197.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 56821444 + 22306729 = 7538^2 + 4723^2 .

It is a cyclic number.

It is not a de Polignac number, because 79128173 - 2² = 79128169 is a prime.

It is a super-2 number, since 2×79128173² = 12522535524635858, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79128143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39564086 + 39564087.

It is an arithmetic number, because the mean of its divisors is an integer number (39564087).

Almost surely, 2^79128173 is an apocalyptic number.

It is an amenable number.

79128173 is a deficient number, since it is larger than the sum of its proper divisors (1).

79128173 is an equidigital number, since it uses as much as digits as its factorization.

79128173 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21168, while the sum is 38.

The square root of 79128173 is about 8895.4017896889. The cubic root of 79128173 is about 429.3159721230.

The spelling of 79128173 in words is "seventy-nine million, one hundred twenty-eight thousand, one hundred seventy-three".