561856685977 has 2 divisors, whose sum is σ = 561856685978. Its totient is φ = 561856685976.

The previous prime is 561856685953. The next prime is 561856686071. The reversal of 561856685977 is 779586658165.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 561856684041 + 1936 = 749571^2 + 44^2 .

It is a cyclic number.

It is not a de Polignac number, because 561856685977 - 2¹⁵ = 561856653209 is a prime.

It is not a weakly prime, because it can be changed into another prime (561856685917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280928342988 + 280928342989.

It is an arithmetic number, because the mean of its divisors is an integer number (280928342989).

Almost surely, 2^561856685977 is an apocalyptic number.

It is an amenable number.

561856685977 is a deficient number, since it is larger than the sum of its proper divisors (1).

561856685977 is an equidigital number, since it uses as much as digits as its factorization.

561856685977 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 762048000, while the sum is 73.

The spelling of 561856685977 in words is "five hundred sixty-one billion, eight hundred fifty-six million, six hundred eighty-five thousand, nine hundred seventy-seven".