90581 has 4 divisors (see below), whose sum is σ = 91200. Its totient is φ = 89964.

The previous prime is 90547. The next prime is 90583. The reversal of 90581 is 18509.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 18509 = 83 ⋅223.

It is a cyclic number.

It is not a de Polignac number, because 90581 - 2¹⁴ = 74197 is a prime.

It is a super-2 number, since 2×90581² = 16409835122, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

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 90581.

It is not an unprimeable number, because it can be changed into a prime (90583) 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, 50 + ... + 428.

It is an arithmetic number, because the mean of its divisors is an integer number (22800).

2⁹⁰⁵⁸¹ is an apocalyptic number.

It is an amenable number.

90581 is a deficient number, since it is larger than the sum of its proper divisors (619).

90581 is a wasteful number, since it uses less digits than its factorization.

90581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 618.

The product of its (nonzero) digits is 360, while the sum is 23.

The square root of 90581 is about 300.9667755750. The cubic root of 90581 is about 44.9102738877.

The spelling of 90581 in words is "ninety thousand, five hundred eighty-one".