20259 has 6 divisors (see below), whose sum is σ = 29276. Its totient is φ = 13500.

The previous prime is 20249. The next prime is 20261. The reversal of 20259 is 95202.

It is not a de Polignac number, because 20259 - 2¹¹ = 18211 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 12 and base 14.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 20259.

It is not an unprimeable number, because it can be changed into a prime (20219) 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, 1117 + ... + 1134.

2²⁰²⁵⁹ is an apocalyptic number.

20259 is a deficient number, since it is larger than the sum of its proper divisors (9017).

20259 is a wasteful number, since it uses less digits than its factorization.

20259 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2257 (or 2254 counting only the distinct ones).

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

The square root of 20259 is about 142.3341139713. The cubic root of 20259 is about 27.2608463402.

It can be divided in two parts, 2025 and 9, that multiplied together give a square (18225 = 135²).

The spelling of 20259 in words is "twenty thousand, two hundred fifty-nine".