23456561 has 2 divisors, whose sum is σ = 23456562. Its totient is φ = 23456560.

The previous prime is 23456539. The next prime is 23456567. The reversal of 23456561 is 16565432.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22090000 + 1366561 = 4700^2 + 1169^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-23456561 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is not a weakly prime, because it can be changed into another prime (23456567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11728280 + 11728281.

It is an arithmetic number, because the mean of its divisors is an integer number (11728281).

Almost surely, 2^23456561 is an apocalyptic number.

It is an amenable number.

23456561 is a deficient number, since it is larger than the sum of its proper divisors (1).

23456561 is an equidigital number, since it uses as much as digits as its factorization.

23456561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21600, while the sum is 32.

The square root of 23456561 is about 4843.1973942841. The cubic root of 23456561 is about 286.2561196991.

The spelling of 23456561 in words is "twenty-three million, four hundred fifty-six thousand, five hundred sixty-one".