20529 has 6 divisors (see below), whose sum is σ = 29666. Its totient is φ = 13680.

The previous prime is 20521. The next prime is 20533. The reversal of 20529 is 92502.

It can be written as a sum of positive squares in only one way, i.e., 18225 + 2304 = 135^2 + 48^2 .

It is not a de Polignac number, because 20529 - 2³ = 20521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20521) 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 5 ways as a sum of consecutive naturals, for example, 1132 + ... + 1149.

2²⁰⁵²⁹ is an apocalyptic number.

It is an amenable number.

20529 is a deficient number, since it is larger than the sum of its proper divisors (9137).

20529 is a wasteful number, since it uses less digits than its factorization.

20529 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2287 (or 2284 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 20529 is about 143.2794472351. The cubic root of 20529 is about 27.3814177735.

The spelling of 20529 in words is "twenty thousand, five hundred twenty-nine".