581665433261 has 24 divisors (see below), whose sum is σ = 648924841152. Its totient is φ = 520881838400.

The previous prime is 581665433243. The next prime is 581665433311. The reversal of 581665433261 is 162334566185.

It is a happy number.

It is not a de Polignac number, because 581665433261 - 2¹⁴ = 581665416877 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 (581665433231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9962225 + ... + 10020441.

It is an arithmetic number, because the mean of its divisors is an integer number (27038535048).

Almost surely, 2^581665433261 is an apocalyptic number.

It is an amenable number.

581665433261 is a deficient number, since it is larger than the sum of its proper divisors (67259407891).

581665433261 is a wasteful number, since it uses less digits than its factorization.

581665433261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59473 (or 59462 counting only the distinct ones).

The product of its digits is 3110400, while the sum is 50.

The spelling of 581665433261 in words is "five hundred eighty-one billion, six hundred sixty-five million, four hundred thirty-three thousand, two hundred sixty-one".