20964 has 12 divisors (see below), whose sum is σ = 48944. Its totient is φ = 6984.

The previous prime is 20963. The next prime is 20981. The reversal of 20964 is 46902.

It is a tau number, because it is divible by the number of its divisors (12).

It is a self number, because there is not a number n which added to its sum of digits gives 20964.

It is not an unprimeable number, because it can be changed into a prime (20963) by changing a digit.

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, 862 + ... + 885.

2²⁰⁹⁶⁴ is an apocalyptic number.

It is an amenable number.

20964 is an abundant number, since it is smaller than the sum of its proper divisors (27980).

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 (24472).

20964 is a wasteful number, since it uses less digits than its factorization.

20964 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1754 (or 1752 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 20964 is about 144.7895023819. The cubic root of 20964 is about 27.5734674655.

The spelling of 20964 in words is "twenty thousand, nine hundred sixty-four".