818984549561 has 2 divisors, whose sum is σ = 818984549562. Its totient is φ = 818984549560.

The previous prime is 818984549527. The next prime is 818984549567. The reversal of 818984549561 is 165945489818.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 657907543225 + 161077006336 = 811115^2 + 401344^2 .

It is a cyclic number.

It is not a de Polignac number, because 818984549561 - 2²² = 818980355257 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 818984549491 and 818984549500.

It is not a weakly prime, because it can be changed into another prime (818984549567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 409492274780 + 409492274781.

It is an arithmetic number, because the mean of its divisors is an integer number (409492274781).

Almost surely, 2^818984549561 is an apocalyptic number.

It is an amenable number.

818984549561 is a deficient number, since it is larger than the sum of its proper divisors (1).

818984549561 is an equidigital number, since it uses as much as digits as its factorization.

818984549561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 99532800, while the sum is 68.

The spelling of 818984549561 in words is "eight hundred eighteen billion, nine hundred eighty-four million, five hundred forty-nine thousand, five hundred sixty-one".