561726806621 has 2 divisors, whose sum is σ = 561726806622. Its totient is φ = 561726806620.

The previous prime is 561726806609. The next prime is 561726806659. The reversal of 561726806621 is 126608627165.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 401466700996 + 160260105625 = 633614^2 + 400325^2 .

It is a cyclic number.

It is not a de Polignac number, because 561726806621 - 2²² = 561722612317 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 561726806621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561726806671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280863403310 + 280863403311.

It is an arithmetic number, because the mean of its divisors is an integer number (280863403311).

Almost surely, 2^561726806621 is an apocalyptic number.

It is an amenable number.

561726806621 is a deficient number, since it is larger than the sum of its proper divisors (1).

561726806621 is an equidigital number, since it uses as much as digits as its factorization.

561726806621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1451520, while the sum is 50.

The spelling of 561726806621 in words is "five hundred sixty-one billion, seven hundred twenty-six million, eight hundred six thousand, six hundred twenty-one".