22005521 has 2 divisors, whose sum is σ = 22005522. Its totient is φ = 22005520.

The previous prime is 22005509. The next prime is 22005523. The reversal of 22005521 is 12550022.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18395521 + 3610000 = 4289^2 + 1900^2 .

It is a cyclic number.

It is not a de Polignac number, because 22005521 - 2¹⁰ = 22004497 is a prime.

Together with 22005523, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 22005521.

It is not a weakly prime, because it can be changed into another prime (22005523) 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, 11002760 + 11002761.

It is an arithmetic number, because the mean of its divisors is an integer number (11002761).

Almost surely, 2^22005521 is an apocalyptic number.

It is an amenable number.

22005521 is a deficient number, since it is larger than the sum of its proper divisors (1).

22005521 is an equidigital number, since it uses as much as digits as its factorization.

22005521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 200, while the sum is 17.

The square root of 22005521 is about 4691.0042634813. The cubic root of 22005521 is about 280.2273705886.

Adding to 22005521 its reverse (12550022), we get a palindrome (34555543).

The spelling of 22005521 in words is "twenty-two million, five thousand, five hundred twenty-one".