86581 has 8 divisors (see below), whose sum is σ = 100224. Its totient is φ = 73920.

The previous prime is 86579. The next prime is 86587. The reversal of 86581 is 18568.

86581 = 33² + 34² + ... + 66².

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 86581 - 2¹ = 86579 is a prime.

It is a super-2 number, since 2×86581² = 14992539122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (86587) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45 + ... + 418.

It is an arithmetic number, because the mean of its divisors is an integer number (12528).

2⁸⁶⁵⁸¹ is an apocalyptic number.

It is an amenable number.

86581 is a deficient number, since it is larger than the sum of its proper divisors (13643).

86581 is a wasteful number, since it uses less digits than its factorization.

86581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 491.

The product of its digits is 1920, while the sum is 28.

The square root of 86581 is about 294.2464953062. The cubic root of 86581 is about 44.2392272711.

It can be divided in two parts, 865 and 81, that added together give a triangular number (946 = T₄₃).

The spelling of 86581 in words is "eighty-six thousand, five hundred eighty-one".