561981385697 has 2 divisors, whose sum is σ = 561981385698. Its totient is φ = 561981385696.

The previous prime is 561981385657. The next prime is 561981385729. The reversal of 561981385697 is 796583189165.

561981385697 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 292122954256 + 269858431441 = 540484^2 + 519479^2 .

It is a cyclic number.

It is not a de Polignac number, because 561981385697 - 2²⁸ = 561712950241 is a prime.

It is not a weakly prime, because it can be changed into another prime (561981385657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280990692848 + 280990692849.

It is an arithmetic number, because the mean of its divisors is an integer number (280990692849).

Almost surely, 2^561981385697 is an apocalyptic number.

It is an amenable number.

561981385697 is a deficient number, since it is larger than the sum of its proper divisors (1).

561981385697 is an equidigital number, since it uses as much as digits as its factorization.

561981385697 is an evil number, because the sum of its binary digits is even.

The product of its digits is 97977600, while the sum is 68.

The spelling of 561981385697 in words is "five hundred sixty-one billion, nine hundred eighty-one million, three hundred eighty-five thousand, six hundred ninety-seven".