81982 has 8 divisors (see below), whose sum is σ = 124200. Its totient is φ = 40584.

The previous prime is 81973. The next prime is 82003. The reversal of 81982 is 28918.

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

It is a self number, because there is not a number n which added to its sum of digits gives 81982.

It is a congruent number.

It is an unprimeable number.

81982 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 244 + ... + 472.

It is an arithmetic number, because the mean of its divisors is an integer number (15525).

2⁸¹⁹⁸² is an apocalyptic number.

81982 is a deficient number, since it is larger than the sum of its proper divisors (42218).

81982 is a wasteful number, since it uses less digits than its factorization.

81982 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410.

The product of its digits is 1152, while the sum is 28.

The square root of 81982 is about 286.3249901772. The cubic root of 81982 is about 43.4416357362.

The spelling of 81982 in words is "eighty-one thousand, nine hundred eighty-two".