20824 has 16 divisors (see below), whose sum is σ = 41400. Its totient is φ = 9792.

The previous prime is 20809. The next prime is 20849. The reversal of 20824 is 42802.

20824 = T₂ + T₃ + ... + T₄₉.

It is a plaindrome in base 7.

It is a zygodrome in base 7.

It is a junction number, because it is equal to n+sod(n) for n = 20798 and 20807.

It is a congruent number.

It is an unprimeable number.

20824 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 in 3 ways as a sum of consecutive naturals, for example, 84 + ... + 220.

2²⁰⁸²⁴ is an apocalyptic number.

It is an amenable number.

20824 is a deficient number, since it is larger than the sum of its proper divisors (20576).

20824 is a wasteful number, since it uses less digits than its factorization.

20824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162 (or 158 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 20824 is about 144.3052320604. The cubic root of 20824 is about 27.5119507287.

It can be divided in two parts, 208 and 24, that added together give a palindrome (232).

The spelling of 20824 in words is "twenty thousand, eight hundred twenty-four".