16866161 has 4 divisors (see below), whose sum is σ = 18163572. Its totient is φ = 15568752.

The previous prime is 16866151. The next prime is 16866163. The reversal of 16866161 is 16166861.

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 1311025 + 15555136 = 1145^2 + 3944^2 .

It is a cyclic number.

It is not a de Polignac number, because 16866161 - 2⁶ = 16866097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16866163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 648686 + ... + 648711.

It is an arithmetic number, because the mean of its divisors is an integer number (4540893).

Almost surely, 2^16866161 is an apocalyptic number.

It is an amenable number.

16866161 is a deficient number, since it is larger than the sum of its proper divisors (1297411).

16866161 is a wasteful number, since it uses less digits than its factorization.

16866161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1297410.

The product of its digits is 10368, while the sum is 35.

The square root of 16866161 is about 4106.8431915524. The cubic root of 16866161 is about 256.4516005434.

The spelling of 16866161 in words is "sixteen million, eight hundred sixty-six thousand, one hundred sixty-one".