51564596561 has 2 divisors, whose sum is σ = 51564596562. Its totient is φ = 51564596560.

The previous prime is 51564596557. The next prime is 51564596569. The reversal of 51564596561 is 16569546515.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 44592346561 + 6972250000 = 211169^2 + 83500^2 .

It is a cyclic number.

It is not a de Polignac number, because 51564596561 - 2² = 51564596557 is a prime.

It is not a weakly prime, because it can be changed into another prime (51564596569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25782298280 + 25782298281.

It is an arithmetic number, because the mean of its divisors is an integer number (25782298281).

Almost surely, 2^51564596561 is an apocalyptic number.

It is an amenable number.

51564596561 is a deficient number, since it is larger than the sum of its proper divisors (1).

51564596561 is an equidigital number, since it uses as much as digits as its factorization.

51564596561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4860000, while the sum is 53.

The spelling of 51564596561 in words is "fifty-one billion, five hundred sixty-four million, five hundred ninety-six thousand, five hundred sixty-one".