561773581 has 2 divisors, whose sum is σ = 561773582. Its totient is φ = 561773580.

The previous prime is 561773579. The next prime is 561773591. The reversal of 561773581 is 185377165.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 363245481 + 198528100 = 19059^2 + 14090^2 .

It is a cyclic number.

It is not a de Polignac number, because 561773581 - 2¹ = 561773579 is a prime.

It is a super-2 number, since 2×561773581² = 631179112619127122, which contains 22 as substring.

Together with 561773579, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561773521) 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, 280886790 + 280886791.

It is an arithmetic number, because the mean of its divisors is an integer number (280886791).

Almost surely, 2^561773581 is an apocalyptic number.

It is an amenable number.

561773581 is a deficient number, since it is larger than the sum of its proper divisors (1).

561773581 is an equidigital number, since it uses as much as digits as its factorization.

561773581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 176400, while the sum is 43.

The square root of 561773581 is about 23701.7632466448. The cubic root of 561773581 is about 825.1263135643.

The spelling of 561773581 in words is "five hundred sixty-one million, seven hundred seventy-three thousand, five hundred eighty-one".