566636561 has 2 divisors, whose sum is σ = 566636562. Its totient is φ = 566636560.

The previous prime is 566636557. The next prime is 566636591. The reversal of 566636561 is 165636665.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 421891600 + 144744961 = 20540^2 + 12031^2 .

It is a cyclic number.

It is not a de Polignac number, because 566636561 - 2² = 566636557 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (566636501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 283318280 + 283318281.

It is an arithmetic number, because the mean of its divisors is an integer number (283318281).

Almost surely, 2^566636561 is an apocalyptic number.

It is an amenable number.

566636561 is a deficient number, since it is larger than the sum of its proper divisors (1).

566636561 is an equidigital number, since it uses as much as digits as its factorization.

566636561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 583200, while the sum is 44.

The square root of 566636561 is about 23804.1290745954. The cubic root of 566636561 is about 827.5003719692.

The spelling of 566636561 in words is "five hundred sixty-six million, six hundred thirty-six thousand, five hundred sixty-one".