85981 has 8 divisors (see below), whose sum is σ = 100224. Its totient is φ = 72240.

The previous prime is 85933. The next prime is 85991. The reversal of 85981 is 18958.

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

It is not a de Polignac number, because 85981 - 2⁷ = 85853 is a prime.

It is a super-2 number, since 2×85981² = 14785464722, which contains 22 as substring.

It is a Duffinian number.

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85931) 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, 411 + ... + 583.

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

2⁸⁵⁹⁸¹ is an apocalyptic number.

It is an amenable number.

85981 is a deficient number, since it is larger than the sum of its proper divisors (14243).

85981 is a wasteful number, since it uses less digits than its factorization.

85981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251.

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

The square root of 85981 is about 293.2251694517. The cubic root of 85981 is about 44.1367987612.

The spelling of 85981 in words is "eighty-five thousand, nine hundred eighty-one".