2221666 has 8 divisors (see below), whose sum is σ = 3352284. Its totient is φ = 1104240.

The previous prime is 2221657. The next prime is 2221669. The reversal of 2221666 is 6661222.

It can be written as a sum of positive squares in 2 ways, for example, as 2187441 + 34225 = 1479^2 + 185^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 2221666.

It is not an unprimeable number, because it can be changed into a prime (2221669) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2865 + ... + 3556.

2^2221666 is an apocalyptic number.

2221666 is a deficient number, since it is larger than the sum of its proper divisors (1130618).

2221666 is a wasteful number, since it uses less digits than its factorization.

2221666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6596.

The product of its digits is 1728, while the sum is 25.

The square root of 2221666 is about 1490.5254107193. The cubic root of 2221666 is about 130.4846994485.

Adding to 2221666 its reverse (6661222), we get a palindrome (8882888).

The spelling of 2221666 in words is "two million, two hundred twenty-one thousand, six hundred sixty-six".