22221666 has 12 divisors (see below), whose sum is σ = 48146982. Its totient is φ = 7407216.

The previous prime is 22221649. The next prime is 22221691. The reversal of 22221666 is 66612222.

It can be written as a sum of positive squares in only one way, i.e., 20439441 + 1782225 = 4521^2 + 1335^2 .

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 617251 + ... + 617286.

Almost surely, 2^22221666 is an apocalyptic number.

22221666 is an abundant number, since it is smaller than the sum of its proper divisors (25925316).

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

22221666 is a wasteful number, since it uses less digits than its factorization.

22221666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1234545 (or 1234542 counting only the distinct ones).

The product of its digits is 3456, while the sum is 27.

The square root of 22221666 is about 4713.9862112654. The cubic root of 22221666 is about 281.1418760677.

Adding to 22221666 its reverse (66612222), we get a palindrome (88833888).

The spelling of 22221666 in words is "twenty-two million, two hundred twenty-one thousand, six hundred sixty-six".