12818554561 has 2 divisors, whose sum is σ = 12818554562. Its totient is φ = 12818554560.

The previous prime is 12818554547. The next prime is 12818554621. The reversal of 12818554561 is 16545581821.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9687480625 + 3131073936 = 98425^2 + 55956^2 .

It is a cyclic number.

It is not a de Polignac number, because 12818554561 - 2¹⁷ = 12818423489 is a prime.

It is not a weakly prime, because it can be changed into another prime (12818554531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6409277280 + 6409277281.

It is an arithmetic number, because the mean of its divisors is an integer number (6409277281).

Almost surely, 2^12818554561 is an apocalyptic number.

It is an amenable number.

12818554561 is a deficient number, since it is larger than the sum of its proper divisors (1).

12818554561 is an equidigital number, since it uses as much as digits as its factorization.

12818554561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 384000, while the sum is 46.

The spelling of 12818554561 in words is "twelve billion, eight hundred eighteen million, five hundred fifty-four thousand, five hundred sixty-one".