20803 has 4 divisors (see below), whose sum is σ = 21168. Its totient is φ = 20440.

The previous prime is 20789. The next prime is 20807. The reversal of 20803 is 30802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 30802 = 2 ⋅15401.

It is a cyclic number.

It is not a de Polignac number, because 20803 - 2⁵ = 20771 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20807) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 76 + ... + 217.

It is an arithmetic number, because the mean of its divisors is an integer number (5292).

2²⁰⁸⁰³ is an apocalyptic number.

20803 is a deficient number, since it is larger than the sum of its proper divisors (365).

20803 is an equidigital number, since it uses as much as digits as its factorization.

20803 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 364.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 20803 is about 144.2324512722. The cubic root of 20803 is about 27.5026994595.

Subtracting 20803 from its reverse (30802), we obtain a palindrome (9999).

The spelling of 20803 in words is "twenty thousand, eight hundred three".