22455721 has 2 divisors, whose sum is σ = 22455722. Its totient is φ = 22455720.

The previous prime is 22455677. The next prime is 22455731. The reversal of 22455721 is 12755422.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20830096 + 1625625 = 4564^2 + 1275^2 .

It is a cyclic number.

It is not a de Polignac number, because 22455721 - 2⁷ = 22455593 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 22455721.

It is not a weakly prime, because it can be changed into another prime (22455731) 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, 11227860 + 11227861.

It is an arithmetic number, because the mean of its divisors is an integer number (11227861).

Almost surely, 2^22455721 is an apocalyptic number.

It is an amenable number.

22455721 is a deficient number, since it is larger than the sum of its proper divisors (1).

22455721 is an equidigital number, since it uses as much as digits as its factorization.

22455721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5600, while the sum is 28.

The square root of 22455721 is about 4738.7467752561. The cubic root of 22455721 is about 282.1254953402.

It can be divided in two parts, 224 and 55721, that added together give a triangular number (55945 = T₃₃₄).

The spelling of 22455721 in words is "twenty-two million, four hundred fifty-five thousand, seven hundred twenty-one".