22211666 has 4 divisors (see below), whose sum is σ = 33317502. Its totient is φ = 11105832.

The previous prime is 22211663. The next prime is 22211677. The reversal of 22211666 is 66611222.

22211666 = 1355² + 1356² + ... + 1366².

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 66611222 = 2 ⋅33305611.

It can be written as a sum of positive squares in only one way, i.e., 12780625 + 9431041 = 3575^2 + 3071^2 .

It is a Curzon number.

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (22211663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5552915 + ... + 5552918.

Almost surely, 2^22211666 is an apocalyptic number.

22211666 is a deficient number, since it is larger than the sum of its proper divisors (11105836).

22211666 is a wasteful number, since it uses less digits than its factorization.

22211666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11105835.

The product of its digits is 1728, while the sum is 26.

The square root of 22211666 is about 4712.9254184636. The cubic root of 22211666 is about 281.0996974031.

Adding to 22211666 its reverse (66611222), we get a palindrome (88822888).

It can be divided in two parts, 222 and 11666, that multiplied together give a palindrome (2589852).

The spelling of 22211666 in words is "twenty-two million, two hundred eleven thousand, six hundred sixty-six".