20504 has 16 divisors (see below), whose sum is σ = 42120. Its totient is φ = 9280.

The previous prime is 20483. The next prime is 20507. The reversal of 20504 is 40502.

20504 = 28² + 29² + ... + 43².

It is a Harshad number since it is a multiple of its sum of digits (11).

It is a pancake number, because a pancake can be divided into 20504 parts by 202 straight cuts.

It is a nialpdrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20507) 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, 29 + ... + 204.

2²⁰⁵⁰⁴ is an apocalyptic number.

It is an amenable number.

20504 is an abundant number, since it is smaller than the sum of its proper divisors (21616).

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 (21060).

20504 is a wasteful number, since it uses less digits than its factorization.

20504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250 (or 246 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 11.

The square root of 20504 is about 143.1921785573. The cubic root of 20504 is about 27.3702983245.

The spelling of 20504 in words is "twenty thousand, five hundred four".