581605681 has 2 divisors, whose sum is σ = 581605682. Its totient is φ = 581605680.

The previous prime is 581605603. The next prime is 581605691. The reversal of 581605681 is 186506185.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 324324081 + 257281600 = 18009^2 + 16040^2 .

It is a cyclic number.

It is not a de Polignac number, because 581605681 - 2²⁵ = 548051249 is a prime.

It is a super-2 number, since 2×581605681² = 676530336342947522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (581605691) 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, 290802840 + 290802841.

It is an arithmetic number, because the mean of its divisors is an integer number (290802841).

Almost surely, 2^581605681 is an apocalyptic number.

It is an amenable number.

581605681 is a deficient number, since it is larger than the sum of its proper divisors (1).

581605681 is an equidigital number, since it uses as much as digits as its factorization.

581605681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 57600, while the sum is 40.

The square root of 581605681 is about 24116.5022546803. The cubic root of 581605681 is about 834.7239605319.

The spelling of 581605681 in words is "five hundred eighty-one million, six hundred five thousand, six hundred eighty-one".