20216 has 24 divisors (see below), whose sum is σ = 45720. Its totient is φ = 8208.

The previous prime is 20201. The next prime is 20219. The reversal of 20216 is 61202.

20216 is nontrivially palindromic in base 6.

It is an Ulam number.

It is a nialpdrome in base 14.

It is a junction number, because it is equal to n+sod(n) for n = 20197 and 20206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20219) by changing a digit.

20216 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 5 ways as a sum of consecutive naturals, for example, 1055 + ... + 1073.

It is an arithmetic number, because the mean of its divisors is an integer number (1905).

2²⁰²¹⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22860).

20216 is an abundant number, since it is smaller than the sum of its proper divisors (25504).

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

20216 is a wasteful number, since it uses less digits than its factorization.

20216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51 (or 28 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 20216 is about 142.1829806974. The cubic root of 20216 is about 27.2415455073.

Adding to 20216 its reverse (61202), we get a palindrome (81418).

The spelling of 20216 in words is "twenty thousand, two hundred sixteen".