2166305 has 4 divisors (see below), whose sum is σ = 2599572. Its totient is φ = 1733040.

The previous prime is 2166289. The next prime is 2166319. The reversal of 2166305 is 5036612.

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 305809 + 1860496 = 553^2 + 1364^2 .

It is not a de Polignac number, because 2166305 - 2⁴ = 2166289 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 216626 + ... + 216635.

It is an arithmetic number, because the mean of its divisors is an integer number (649893).

2^2166305 is an apocalyptic number.

It is an amenable number.

2166305 is a deficient number, since it is larger than the sum of its proper divisors (433267).

2166305 is an equidigital number, since it uses as much as digits as its factorization.

2166305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 433266.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 2166305 is about 1471.8372872026. The cubic root of 2166305 is about 129.3917343209.

The spelling of 2166305 in words is "two million, one hundred sixty-six thousand, three hundred five".