16891 has 8 divisors (see below), whose sum is σ = 20480.
Its totient is φ = 13608.
The previous prime is 16889. The next prime is 16901. The reversal of 16891 is 19861.
16891 = 282 + 292 + ... + 412.
It is a sphenic number, since it is the product of 3 distinct primes.
It is not a de Polignac number, because 16891 - 21 = 16889 is a prime.
16891 is a strobogrammatic number because it is the same when read upside-down.
It is a Duffinian number.
It is not an unprimeable number, because it can be changed into a prime (16811) by changing a digit.
It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70 + ... + 196.
It is an arithmetic number, because the mean of its divisors is an integer number (2560).
216891 is an apocalyptic number.
16891 is a deficient number, since it is larger than the sum of its proper divisors (3589).
16891 is a wasteful number, since it uses less digits than its factorization.
16891 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 153.
The product of its digits is 432, while the sum is 25.
The square root of 16891 is about 129.9653800056.
The cubic root of 16891 is about 25.6577431921.
The spelling of 16891 in words is "sixteen thousand, eight hundred ninety-one".