581276661 has 24 divisors (see below), whose sum is σ = 903345120. Its totient is φ = 331504992.

The previous prime is 581276651. The next prime is 581276693. The reversal of 581276661 is 166672185.

It is not a de Polignac number, because 581276661 - 2¹¹ = 581274613 is a prime.

It is a super-3 number, since 3×581276661³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (581276651) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 76795 + ... + 84023.

It is an arithmetic number, because the mean of its divisors is an integer number (37639380).

Almost surely, 2^581276661 is an apocalyptic number.

It is an amenable number.

581276661 is a deficient number, since it is larger than the sum of its proper divisors (322068459).

581276661 is a wasteful number, since it uses less digits than its factorization.

581276661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7793 (or 7786 counting only the distinct ones).

The product of its digits is 120960, while the sum is 42.

The square root of 581276661 is about 24109.6798195248. The cubic root of 581276661 is about 834.5665270154.

The spelling of 581276661 in words is "five hundred eighty-one million, two hundred seventy-six thousand, six hundred sixty-one".