16820 has 18 divisors (see below), whose sum is σ = 36582. Its totient is φ = 6496.

The previous prime is 16811. The next prime is 16823. The reversal of 16820 is 2861.

16820 is an esthetic number in base 12, because in such base its adjacent digits differ by 1.

It can be written as a sum of positive squares in 3 ways, for example, as 1936 + 14884 = 44^2 + 122^2 .

16820 is an undulating number in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16823) 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, 566 + ... + 594.

16820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 16820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18291).

16820 is an abundant number, since it is smaller than the sum of its proper divisors (19762).

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

16820 is a wasteful number, since it uses less digits than its factorization.

16820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67 (or 36 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 16820 is about 129.6919426950. The cubic root of 16820 is about 25.6217425961.

The spelling of 16820 in words is "sixteen thousand, eight hundred twenty".