2166784 has 39 divisors (see below), whose sum is σ = 4529623. Its totient is φ = 1036288.

The previous prime is 2166763. The next prime is 2166797. The reversal of 2166784 is 4876612.

The square root of 2166784 is 1472.

It is a perfect power (a square), and thus also a powerful number.

It is a Smith number, since the sum of its digits (34) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is an unprimeable number.

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 2 ways as a sum of consecutive naturals, for example, 94197 + ... + 94219.

2^2166784 is an apocalyptic number.

2166784 is the 1472-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2166784

2166784 is an abundant number, since it is smaller than the sum of its proper divisors (2362839).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2166784 is an frugal number, since it uses more digits than its factorization.

2166784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70 (or 25 counting only the distinct ones).

The product of its digits is 16128, while the sum is 34.

The cubic root of 2166784 is about 129.4012703854.

The spelling of 2166784 in words is "two million, one hundred sixty-six thousand, seven hundred eighty-four".