20982 has 16 divisors (see below), whose sum is σ = 45360. Its totient is φ = 6432.

The previous prime is 20981. The next prime is 20983. The reversal of 20982 is 28902.

20982 = 34² + 35² + ... + 46².

It is an interprime number because it is at equal distance from previous prime (20981) and next prime (20983).

It is a nialpdrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20981) 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, 57 + ... + 212.

It is an arithmetic number, because the mean of its divisors is an integer number (2835).

2²⁰⁹⁸² is an apocalyptic number.

20982 is an abundant number, since it is smaller than the sum of its proper divisors (24378).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22680).

20982 is a wasteful number, since it uses less digits than its factorization.

20982 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 287.

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 20982 is about 144.8516482474. The cubic root of 20982 is about 27.5813568701.

The spelling of 20982 in words is "twenty thousand, nine hundred eighty-two".