581400661 has 2 divisors, whose sum is σ = 581400662. Its totient is φ = 581400660.

The previous prime is 581400653. The next prime is 581400679. The reversal of 581400661 is 166004185.

581400661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 380640100 + 200760561 = 19510^2 + 14169^2 .

It is a cyclic number.

It is not a de Polignac number, because 581400661 - 2³ = 581400653 is a prime.

It is a super-2 number, since 2×581400661² = 676053457222473842, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (581400761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 290700330 + 290700331.

It is an arithmetic number, because the mean of its divisors is an integer number (290700331).

Almost surely, 2^581400661 is an apocalyptic number.

It is an amenable number.

581400661 is a deficient number, since it is larger than the sum of its proper divisors (1).

581400661 is an equidigital number, since it uses as much as digits as its factorization.

581400661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 581400661 is about 24112.2512636212. The cubic root of 581400661 is about 834.6258670270.

The spelling of 581400661 in words is "five hundred eighty-one million, four hundred thousand, six hundred sixty-one".