913581 has 12 divisors (see below), whose sum is σ = 1336608. Its totient is φ = 601224.

The previous prime is 913579. The next prime is 913589. The reversal of 913581 is 185319.

It is not a de Polignac number, because 913581 - 2¹ = 913579 is a prime.

It is a super-2 number, since 2×913581² = 1669260487122, which contains 22 as substring.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 913581.

It is not an unprimeable number, because it can be changed into a prime (913589) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 136 + ... + 1358.

It is an arithmetic number, because the mean of its divisors is an integer number (111384).

2⁹¹³⁵⁸¹ is an apocalyptic number.

It is an amenable number.

913581 is a deficient number, since it is larger than the sum of its proper divisors (423027).

913581 is a wasteful number, since it uses less digits than its factorization.

913581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1312 (or 1309 counting only the distinct ones).

The product of its digits is 1080, while the sum is 27.

The square root of 913581 is about 955.8143125105. The cubic root of 913581 is about 97.0321571208.

It can be divided in two parts, 9135 and 81, that added together give a square (9216 = 96²).

The spelling of 913581 in words is "nine hundred thirteen thousand, five hundred eighty-one".