79809173 has 2 divisors, whose sum is σ = 79809174. Its totient is φ = 79809172.

The previous prime is 79809137. The next prime is 79809179. The reversal of 79809173 is 37190897.

Together with previous prime (79809137) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58951684 + 20857489 = 7678^2 + 4567^2 .

It is an emirp because it is prime and its reverse (37190897) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 79809173 - 2⁸ = 79808917 is a prime.

It is equal to p_4658939 and since 79809173 and 4658939 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79809179) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39904586 + 39904587.

It is an arithmetic number, because the mean of its divisors is an integer number (39904587).

Almost surely, 2^79809173 is an apocalyptic number.

It is an amenable number.

79809173 is a deficient number, since it is larger than the sum of its proper divisors (1).

79809173 is an equidigital number, since it uses as much as digits as its factorization.

79809173 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 95256, while the sum is 44.

The square root of 79809173 is about 8933.5979873733. The cubic root of 79809173 is about 430.5440616459.

The spelling of 79809173 in words is "seventy-nine million, eight hundred nine thousand, one hundred seventy-three".