16840 has 16 divisors (see below), whose sum is σ = 37980. Its totient is φ = 6720.

The previous prime is 16831. The next prime is 16843. The reversal of 16840 is 4861.

It can be written as a sum of positive squares in 2 ways, for example, as 13924 + 2916 = 118^2 + 54^2 .

It is not an unprimeable number, because it can be changed into a prime (16843) by changing a digit.

16840 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 171 + ... + 250.

2¹⁶⁸⁴⁰ is an apocalyptic number.

16840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

16840 is an abundant number, since it is smaller than the sum of its proper divisors (21140).

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 (18990).

16840 is a wasteful number, since it uses less digits than its factorization.

16840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 432 (or 428 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 16840 is about 129.7690255801. The cubic root of 16840 is about 25.6318938422.

The spelling of 16840 in words is "sixteen thousand, eight hundred forty".