89581 has 4 divisors (see below), whose sum is σ = 92700. Its totient is φ = 86464.

The previous prime is 89567. The next prime is 89591. The reversal of 89581 is 18598.

89581 = T₂₄ + T₂₅ + ... + T₈₁.

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 67081 + 22500 = 259^2 + 150^2 .

It is a cyclic number.

It is not a de Polignac number, because 89581 - 2⁹ = 89069 is a prime.

It is a super-2 number, since 2×89581² = 16049511122, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (89501) 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, 1516 + ... + 1573.

It is an arithmetic number, because the mean of its divisors is an integer number (23175).

2⁸⁹⁵⁸¹ is an apocalyptic number.

It is an amenable number.

89581 is a deficient number, since it is larger than the sum of its proper divisors (3119).

89581 is a wasteful number, since it uses less digits than its factorization.

89581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3118.

The product of its digits is 2880, while the sum is 31.

The square root of 89581 is about 299.3008519868. The cubic root of 89581 is about 44.7443944999.

The spelling of 89581 in words is "eighty-nine thousand, five hundred eighty-one".