581586661 has 4 divisors (see below), whose sum is σ = 582968524. Its totient is φ = 580204800.

The previous prime is 581586647. The next prime is 581586673. The reversal of 581586661 is 166685185.

581586661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14861025 + 566725636 = 3855^2 + 23806^2 .

It is a cyclic number.

It is not a de Polignac number, because 581586661 - 2⁹ = 581586149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (581586641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 690300 + ... + 691141.

It is an arithmetic number, because the mean of its divisors is an integer number (145742131).

Almost surely, 2^581586661 is an apocalyptic number.

It is an amenable number.

581586661 is a deficient number, since it is larger than the sum of its proper divisors (1381863).

581586661 is a wasteful number, since it uses less digits than its factorization.

581586661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1381862.

The product of its digits is 345600, while the sum is 46.

The square root of 581586661 is about 24116.1079156650. The cubic root of 581586661 is about 834.7148612267.

The spelling of 581586661 in words is "five hundred eighty-one million, five hundred eighty-six thousand, six hundred sixty-one".