20782 has 4 divisors (see below), whose sum is σ = 31176. Its totient is φ = 10390.

The previous prime is 20773. The next prime is 20789. The reversal of 20782 is 28702.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20789) by changing a digit.

20782 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 as a sum of consecutive naturals, namely, 5194 + ... + 5197.

It is an arithmetic number, because the mean of its divisors is an integer number (7794).

2²⁰⁷⁸² is an apocalyptic number.

20782 is a deficient number, since it is larger than the sum of its proper divisors (10394).

20782 is a wasteful number, since it uses less digits than its factorization.

20782 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10393.

The product of its (nonzero) digits is 224, while the sum is 19.

The square root of 20782 is about 144.1596337398. The cubic root of 20782 is about 27.4934419624.

It can be divided in two parts, 2078 and 2, that added together give a triangular number (2080 = T₆₄).

The spelling of 20782 in words is "twenty thousand, seven hundred eighty-two".