20616 has 16 divisors (see below), whose sum is σ = 51600. Its totient is φ = 6864.

The previous prime is 20611. The next prime is 20627. The reversal of 20616 is 61602.

It is a nialpdrome in base 12.

It is a junction number, because it is equal to n+sod(n) for n = 20595 and 20604.

It is not an unprimeable number, because it can be changed into a prime (20611) 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, 406 + ... + 453.

It is an arithmetic number, because the mean of its divisors is an integer number (3225).

2²⁰⁶¹⁶ is an apocalyptic number.

It is an amenable number.

20616 is an abundant number, since it is smaller than the sum of its proper divisors (30984).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25800).

20616 is a wasteful number, since it uses less digits than its factorization.

20616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 868 (or 864 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 20616 is about 143.5827287664. The cubic root of 20616 is about 27.4200432316.

It can be divided in two parts, 206 and 16, that added together give a palindrome (222).

The spelling of 20616 in words is "twenty thousand, six hundred sixteen".