22285721 has 2 divisors, whose sum is σ = 22285722. Its totient is φ = 22285720.

The previous prime is 22285709. The next prime is 22285723. The reversal of 22285721 is 12758222.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21160000 + 1125721 = 4600^2 + 1061^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-22285721 is a prime.

Together with 22285723, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (22285723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11142860 + 11142861.

It is an arithmetic number, because the mean of its divisors is an integer number (11142861).

Almost surely, 2^22285721 is an apocalyptic number.

It is an amenable number.

22285721 is a deficient number, since it is larger than the sum of its proper divisors (1).

22285721 is an equidigital number, since it uses as much as digits as its factorization.

22285721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4480, while the sum is 29.

The square root of 22285721 is about 4720.7754659590. The cubic root of 22285721 is about 281.4117518283.

The spelling of 22285721 in words is "twenty-two million, two hundred eighty-five thousand, seven hundred twenty-one".