89981 has 8 divisors (see below), whose sum is σ = 97920. Its totient is φ = 82368.

The previous prime is 89977. The next prime is 89983. The reversal of 89981 is 18998.

89981 = 34² + 35² + ... + 67².

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 89981 - 2² = 89977 is a prime.

It is a super-2 number, since 2×89981² = 16193160722, 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 89981.

It is not an unprimeable number, because it can be changed into a prime (89983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1100 + ... + 1178.

It is an arithmetic number, because the mean of its divisors is an integer number (12240).

2⁸⁹⁹⁸¹ is an apocalyptic number.

It is an amenable number.

89981 is a deficient number, since it is larger than the sum of its proper divisors (7939).

89981 is a wasteful number, since it uses less digits than its factorization.

89981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163.

The product of its digits is 5184, while the sum is 35.

The square root of 89981 is about 299.9683316619. The cubic root of 89981 is about 44.8108936625.

The spelling of 89981 in words is "eighty-nine thousand, nine hundred eighty-one".