16851 has 8 divisors (see below), whose sum is σ = 23184. Its totient is φ = 10880.

The previous prime is 16843. The next prime is 16871. The reversal of 16851 is 15861.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 16851 - 2³ = 16843 is a prime.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (16811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55 + ... + 191.

It is an arithmetic number, because the mean of its divisors is an integer number (2898).

2¹⁶⁸⁵¹ is an apocalyptic number.

16851 is a deficient number, since it is larger than the sum of its proper divisors (6333).

16851 is a wasteful number, since it uses less digits than its factorization.

16851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181.

The product of its digits is 240, while the sum is 21.

The square root of 16851 is about 129.8114016564. The cubic root of 16851 is about 25.6374736020.

Subtracting from 16851 its reverse (15861), we obtain a triangular number (990 = T₄₄).

The spelling of 16851 in words is "sixteen thousand, eight hundred fifty-one".