20525 has 6 divisors (see below), whose sum is σ = 25482. Its totient is φ = 16400.

The previous prime is 20521. The next prime is 20533. The reversal of 20525 is 52502.

It can be written as a sum of positive squares in 3 ways, for example, as 361 + 20164 = 19^2 + 142^2 .

It is not a de Polignac number, because 20525 - 2² = 20521 is a prime.

It is a house number.

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 11.

It is a nialpdrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20521) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 386 + ... + 435.

It is an arithmetic number, because the mean of its divisors is an integer number (4247).

2²⁰⁵²⁵ is an apocalyptic number.

20525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20525 is a deficient number, since it is larger than the sum of its proper divisors (4957).

20525 is an equidigital number, since it uses as much as digits as its factorization.

20525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 831 (or 826 counting only the distinct ones).

The product of its (nonzero) digits is 100, while the sum is 14.

The square root of 20525 is about 143.2654878189. The cubic root of 20525 is about 27.3796392685.

It can be divided in two parts, 20 and 525, that added together give a palindrome (545).

The spelling of 20525 in words is "twenty thousand, five hundred twenty-five".