2221806 has 24 divisors (see below), whose sum is σ = 4637880. Its totient is φ = 708736.

The previous prime is 2221789. The next prime is 2221829. The reversal of 2221806 is 6081222.

It is a hoax number, since the sum of its digits (21) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19606 + ... + 19718.

It is an arithmetic number, because the mean of its divisors is an integer number (193245).

2^2221806 is an apocalyptic number.

2221806 is an abundant number, since it is smaller than the sum of its proper divisors (2416074).

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

2221806 is a wasteful number, since it uses less digits than its factorization.

2221806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260 (or 147 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 2221806 is about 1490.5723732848. The cubic root of 2221806 is about 130.4874402557.

The spelling of 2221806 in words is "two million, two hundred twenty-one thousand, eight hundred six".