20624 has 10 divisors (see below), whose sum is σ = 39990. Its totient is φ = 10304.

The previous prime is 20611. The next prime is 20627. The reversal of 20624 is 42602.

It can be written as a sum of positive squares in only one way, i.e., 19600 + 1024 = 140^2 + 32^2 .

It is a plaindrome in base 5.

It is a nialpdrome in base 14.

It is a junction number, because it is equal to n+sod(n) for n = 20599 and 20608.

It is not an unprimeable number, because it can be changed into a prime (20627) by changing a digit.

20624 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, 629 + ... + 660.

It is an arithmetic number, because the mean of its divisors is an integer number (3999).

2²⁰⁶²⁴ is an apocalyptic number.

It is an amenable number.

20624 is a deficient number, since it is larger than the sum of its proper divisors (19366).

20624 is a wasteful number, since it uses less digits than its factorization.

20624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1297 (or 1291 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 20624 is about 143.6105845681. The cubic root of 20624 is about 27.4235895383.

The spelling of 20624 in words is "twenty thousand, six hundred twenty-four".