79071221 has 2 divisors, whose sum is σ = 79071222. Its totient is φ = 79071220.

The previous prime is 79071193. The next prime is 79071229. The reversal of 79071221 is 12217097.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50608996 + 28462225 = 7114^2 + 5335^2 .

It is an emirp because it is prime and its reverse (12217097) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 79071221 - 2¹⁰ = 79070197 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79071229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39535610 + 39535611.

It is an arithmetic number, because the mean of its divisors is an integer number (39535611).

Almost surely, 2^79071221 is an apocalyptic number.

It is an amenable number.

79071221 is a deficient number, since it is larger than the sum of its proper divisors (1).

79071221 is an equidigital number, since it uses as much as digits as its factorization.

79071221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1764, while the sum is 29.

The square root of 79071221 is about 8892.2000089966. The cubic root of 79071221 is about 429.2129482539.

The spelling of 79071221 in words is "seventy-nine million, seventy-one thousand, two hundred twenty-one".