561131761 has 2 divisors, whose sum is σ = 561131762. Its totient is φ = 561131760.

The previous prime is 561131737. The next prime is 561131773. The reversal of 561131761 is 167131165.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 429318400 + 131813361 = 20720^2 + 11481^2 .

It is a cyclic number.

It is not a de Polignac number, because 561131761 - 2⁵ = 561131729 is a prime.

It is a super-2 number, since 2×561131761² = 629737706405922242, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (561137761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280565880 + 280565881.

It is an arithmetic number, because the mean of its divisors is an integer number (280565881).

Almost surely, 2^561131761 is an apocalyptic number.

It is an amenable number.

561131761 is a deficient number, since it is larger than the sum of its proper divisors (1).

561131761 is an equidigital number, since it uses as much as digits as its factorization.

561131761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3780, while the sum is 31.

The square root of 561131761 is about 23688.2198782433. The cubic root of 561131761 is about 824.8119613072.

The spelling of 561131761 in words is "five hundred sixty-one million, one hundred thirty-one thousand, seven hundred sixty-one".