20286 has 36 divisors (see below), whose sum is σ = 53352. Its totient is φ = 5544.

The previous prime is 20269. The next prime is 20287. The reversal of 20286 is 68202.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20287) by changing a digit.

20286 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 871 + ... + 893.

It is an arithmetic number, because the mean of its divisors is an integer number (1482).

2²⁰²⁸⁶ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20286, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26676).

20286 is an abundant number, since it is smaller than the sum of its proper divisors (33066).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20286 is a wasteful number, since it uses less digits than its factorization.

20286 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45 (or 35 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 20286 is about 142.4289296456. The cubic root of 20286 is about 27.2729515133.

Adding to 20286 its reverse (68202), we get a palindrome (88488).

The spelling of 20286 in words is "twenty thousand, two hundred eighty-six".