16641 has 9 divisors (see below), whose sum is σ = 24609.
Its totient is φ = 10836.
The previous prime is 16633. The next prime is 16649. The reversal of 16641 is 14661.
16641 = T128 + T129.
The square root of 16641 is 129.
It is a perfect power (a square), and thus also a powerful number.
16641 is a `hidden beast` number, since 1 + 664 + 1 = 666.
It is an interprime number because it is at equal distance from previous prime (16633) and next prime (16649).
It is a tau number, because it is divible by the number of its divisors (9).
It is not a de Polignac number, because 16641 - 23 = 16633 is a prime.
It is a plaindrome in base 11.
It is a nialpdrome in base 13.
It is not an unprimeable number, because it can be changed into a prime (16649) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (3) of ones.
It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 366 + ... + 408.
It is a Proth number, since it is equal to 65 ⋅ 28 + 1 and 65 < 28.
216641 is an apocalyptic number.
16641 is the 129-th square number.
16641 is the 65-th centered octagonal number.
It is an amenable number.
16641 is a deficient number, since it is larger than the sum of its proper divisors (7968).
16641 is an equidigital number, since it uses as much as digits as its factorization.
16641 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 92 (or 46 counting only the distinct ones).
The product of its digits is 144, while the sum is 18.
The cubic root of 16641 is about 25.5305286038.
Multiplying 16641 by its product of digits (144), we get a square (2396304 = 15482).
The spelling of 16641 in words is "sixteen thousand, six hundred forty-one".