20530 has 8 divisors (see below), whose sum is σ = 36972. Its totient is φ = 8208.

The previous prime is 20521. The next prime is 20533. The reversal of 20530 is 3502.

20530 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 20449 + 81 = 143^2 + 9^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Harshad number since it is a multiple of its sum of digits (10), and also a Moran number because the ratio is a prime number: 2053 = 20530 / (2 + 0 + 5 + 3 + 0).

20530 is strictly pandigital in base 6.

It is a plaindrome in base 7.

It is not an unprimeable number, because it can be changed into a prime (20533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1017 + ... + 1036.

2²⁰⁵³⁰ is an apocalyptic number.

20530 is a deficient number, since it is larger than the sum of its proper divisors (16442).

20530 is a wasteful number, since it uses less digits than its factorization.

20530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2060.

The product of its (nonzero) digits is 30, while the sum is 10.

The square root of 20530 is about 143.2829368767. The cubic root of 20530 is about 27.3818623636.

The spelling of 20530 in words is "twenty thousand, five hundred thirty".