20485 has 8 divisors (see below), whose sum is σ = 26136. Its totient is φ = 15360.

The previous prime is 20483. The next prime is 20507. The reversal of 20485 is 58402.

20485 = 6² + 7² + ... + 39².

It is a happy number.

20485 is nontrivially palindromic in base 2, base 4, base 8 and base 16.

20485 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 4 ways, for example, as 6561 + 13924 = 81^2 + 118^2 .

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

It is not a de Polignac number, because 20485 - 2¹ = 20483 is a prime.

It is a Duffinian number.

20485 is strictly pandigital in base 6.

20485 is a lucky number.

It is a nialpdrome in base 12.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20483) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36 + ... + 205.

It is an arithmetic number, because the mean of its divisors is an integer number (3267).

20485 is a Friedman number, since it can be written as 5*(8^4+2^0), using all its digits and the basic arithmetic operations.

2²⁰⁴⁸⁵ is an apocalyptic number.

It is an amenable number.

20485 is a deficient number, since it is larger than the sum of its proper divisors (5651).

20485 is a wasteful number, since it uses less digits than its factorization.

20485 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 263.

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 20485 is about 143.1258187750. The cubic root of 20485 is about 27.3618414968.

Adding to 20485 its reverse (58402), we get a palindrome (78887).

It can be divided in two parts, 204 and 85, that added together give a square (289 = 17²).

The spelling of 20485 in words is "twenty thousand, four hundred eighty-five".