83981 has 4 divisors (see below), whose sum is σ = 84732. Its totient is φ = 83232.

The previous prime is 83969. The next prime is 83983. The reversal of 83981 is 18938.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 16900 + 67081 = 130^2 + 259^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-83981 is a prime.

It is a super-2 number, since 2×83981² = 14105616722, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 6.

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 83981.

It is not an unprimeable number, because it can be changed into a prime (83983) 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, 170 + ... + 443.

It is an arithmetic number, because the mean of its divisors is an integer number (21183).

2⁸³⁹⁸¹ is an apocalyptic number.

It is an amenable number.

83981 is a deficient number, since it is larger than the sum of its proper divisors (751).

83981 is a wasteful number, since it uses less digits than its factorization.

83981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 750.

The product of its digits is 1728, while the sum is 29.

The square root of 83981 is about 289.7947549560. The cubic root of 83981 is about 43.7918891315.

The spelling of 83981 in words is "eighty-three thousand, nine hundred eighty-one".