79197221 has 2 divisors, whose sum is σ = 79197222. Its totient is φ = 79197220.

The previous prime is 79197193. The next prime is 79197247. The reversal of 79197221 is 12279197.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 73017025 + 6180196 = 8545^2 + 2486^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-79197221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79197721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39598610 + 39598611.

It is an arithmetic number, because the mean of its divisors is an integer number (39598611).

Almost surely, 2^79197221 is an apocalyptic number.

It is an amenable number.

79197221 is a deficient number, since it is larger than the sum of its proper divisors (1).

79197221 is an equidigital number, since it uses as much as digits as its factorization.

79197221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15876, while the sum is 38.

The square root of 79197221 is about 8899.2820496937. The cubic root of 79197221 is about 429.4408108916.

The spelling of 79197221 in words is "seventy-nine million, one hundred ninety-seven thousand, two hundred twenty-one".