16500665 has 4 divisors (see below), whose sum is σ = 19800804. Its totient is φ = 13200528.

The previous prime is 16500647. The next prime is 16500677. The reversal of 16500665 is 56600561.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10310521 + 6190144 = 3211^2 + 2488^2 .

It is a cyclic number.

It is not a de Polignac number, because 16500665 - 2¹⁰ = 16499641 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1650062 + ... + 1650071.

It is an arithmetic number, because the mean of its divisors is an integer number (4950201).

Almost surely, 2^16500665 is an apocalyptic number.

It is an amenable number.

16500665 is a deficient number, since it is larger than the sum of its proper divisors (3300139).

16500665 is an equidigital number, since it uses as much as digits as its factorization.

16500665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3300138.

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 16500665 is about 4062.1010573347. The cubic root of 16500665 is about 254.5855885813.

The spelling of 16500665 in words is "sixteen million, five hundred thousand, six hundred sixty-five".