22297721 has 2 divisors, whose sum is σ = 22297722. Its totient is φ = 22297720.

The previous prime is 22297703. The next prime is 22297729. The reversal of 22297721 is 12779222.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22278400 + 19321 = 4720^2 + 139^2 .

It is a cyclic number.

It is not a de Polignac number, because 22297721 - 2⁶ = 22297657 is a prime.

It is not a weakly prime, because it can be changed into another prime (22297729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11148860 + 11148861.

It is an arithmetic number, because the mean of its divisors is an integer number (11148861).

Almost surely, 2^22297721 is an apocalyptic number.

It is an amenable number.

22297721 is a deficient number, since it is larger than the sum of its proper divisors (1).

22297721 is an equidigital number, since it uses as much as digits as its factorization.

22297721 is an odious number, because the sum of its binary digits is odd.

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

The square root of 22297721 is about 4722.0462725391. The cubic root of 22297721 is about 281.4622525515.

The spelling of 22297721 in words is "twenty-two million, two hundred ninety-seven thousand, seven hundred twenty-one".