79722221 has 2 divisors, whose sum is σ = 79722222. Its totient is φ = 79722220.

The previous prime is 79722217. The next prime is 79722239. The reversal of 79722221 is 12222797.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54612100 + 25110121 = 7390^2 + 5011^2 .

It is a cyclic number.

It is not a de Polignac number, because 79722221 - 2² = 79722217 is a prime.

It is equal to p_4654175 and since 79722221 and 4654175 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 (79722211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39861110 + 39861111.

It is an arithmetic number, because the mean of its divisors is an integer number (39861111).

Almost surely, 2^79722221 is an apocalyptic number.

It is an amenable number.

79722221 is a deficient number, since it is larger than the sum of its proper divisors (1).

79722221 is an equidigital number, since it uses as much as digits as its factorization.

79722221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7056, while the sum is 32.

The square root of 79722221 is about 8928.7300888760. The cubic root of 79722221 is about 430.3876457445.

The spelling of 79722221 in words is "seventy-nine million, seven hundred twenty-two thousand, two hundred twenty-one".