20836 has 6 divisors (see below), whose sum is σ = 36470. Its totient is φ = 10416.

The previous prime is 20809. The next prime is 20849. The reversal of 20836 is 63802.

It can be written as a sum of positive squares in only one way, i.e., 20736 + 100 = 144^2 + 10^2 .

It is an unprimeable number.

20836 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2601 + ... + 2608.

2²⁰⁸³⁶ is an apocalyptic number.

It is an amenable number.

20836 is a deficient number, since it is larger than the sum of its proper divisors (15634).

20836 is a wasteful number, since it uses less digits than its factorization.

20836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5213 (or 5211 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 20836 is about 144.3468046061. The cubic root of 20836 is about 27.5172343759.

The spelling of 20836 in words is "twenty thousand, eight hundred thirty-six".