16551 has 8 divisors (see below), whose sum is σ = 24560. Its totient is φ = 11016.

The previous prime is 16547. The next prime is 16553. The reversal of 16551 is 15561.

It is not a de Polignac number, because 16551 - 2² = 16547 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16553) 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, 280 + ... + 333.

It is an arithmetic number, because the mean of its divisors is an integer number (3070).

2¹⁶⁵⁵¹ is an apocalyptic number.

16551 is a deficient number, since it is larger than the sum of its proper divisors (8009).

16551 is an equidigital number, since it uses as much as digits as its factorization.

16551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 622 (or 616 counting only the distinct ones).

The product of its digits is 150, while the sum is 18.

The square root of 16551 is about 128.6506898543. The cubic root of 16551 is about 25.4844195481.

Subtracting from 16551 its reverse (15561), we obtain a triangular number (990 = T₄₄).

It can be divided in two parts, 165 and 51, that added together give a cube (216 = 6³).

The spelling of 16551 in words is "sixteen thousand, five hundred fifty-one".