20766 has 8 divisors (see below), whose sum is σ = 41544. Its totient is φ = 6920.

The previous prime is 20759. The next prime is 20771. The reversal of 20766 is 66702.

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

20766 is an admirable number.

It is a plaindrome in base 11.

It is a congruent number.

It is an unprimeable number.

20766 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, 1725 + ... + 1736.

It is an arithmetic number, because the mean of its divisors is an integer number (5193).

2²⁰⁷⁶⁶ is an apocalyptic number.

20766 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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 (20772).

20766 is a wasteful number, since it uses less digits than its factorization.

20766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3466.

The product of its (nonzero) digits is 504, while the sum is 21.

The square root of 20766 is about 144.1041290179. The cubic root of 20766 is about 27.4863844445.

The spelling of 20766 in words is "twenty thousand, seven hundred sixty-six".