20284 has 12 divisors (see below), whose sum is σ = 38808. Its totient is φ = 9200.

The previous prime is 20269. The next prime is 20287. The reversal of 20284 is 48202.

20284 is nontrivially palindromic in base 8.

It is a super-2 number, since 2×20284² = 822881312, which contains 22 as substring.

It is an Ulam number.

20284 is an undulating number in base 8.

It is a congruent number.

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

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 187 + ... + 274.

It is an arithmetic number, because the mean of its divisors is an integer number (3234).

2²⁰²⁸⁴ is an apocalyptic number.

It is an amenable number.

20284 is a deficient number, since it is larger than the sum of its proper divisors (18524).

20284 is a wasteful number, since it uses less digits than its factorization.

20284 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 476 (or 474 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 20284 is about 142.4219084270. The cubic root of 20284 is about 27.2720552023.

Adding to 20284 its reverse (48202), we get a palindrome (68486).

The spelling of 20284 in words is "twenty thousand, two hundred eighty-four".