22507561 has 2 divisors, whose sum is σ = 22507562. Its totient is φ = 22507560.

The previous prime is 22507559. The next prime is 22507601. The reversal of 22507561 is 16570522.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22505536 + 2025 = 4744^2 + 45^2 .

It is a cyclic number.

It is not a de Polignac number, because 22507561 - 2¹ = 22507559 is a prime.

Together with 22507559, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (22507061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11253780 + 11253781.

It is an arithmetic number, because the mean of its divisors is an integer number (11253781).

Almost surely, 2^22507561 is an apocalyptic number.

It is an amenable number.

22507561 is a deficient number, since it is larger than the sum of its proper divisors (1).

22507561 is an equidigital number, since it uses as much as digits as its factorization.

22507561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4200, while the sum is 28.

The square root of 22507561 is about 4744.2134226866. The cubic root of 22507561 is about 282.3424281157.

The spelling of 22507561 in words is "twenty-two million, five hundred seven thousand, five hundred sixty-one".