222116661 has 40 divisors (see below), whose sum is σ = 367049144. Its totient is φ = 132969600.

The previous prime is 222116647. The next prime is 222116683. The reversal of 222116661 is 166611222.

It can be written as a sum of positive squares in 4 ways, for example, as 74494161 + 147622500 = 8631^2 + 12150^2 .

It is not a de Polignac number, because 222116661 - 2¹⁸ = 221854517 is a prime.

It is a super-2 number, since 2×222116661² = 98671622187577842, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (222116641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 36111 + ... + 41811.

Almost surely, 2^222116661 is an apocalyptic number.

It is an amenable number.

222116661 is a deficient number, since it is larger than the sum of its proper divisors (144932483).

222116661 is a wasteful number, since it uses less digits than its factorization.

222116661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5763 (or 5754 counting only the distinct ones).

The product of its digits is 1728, while the sum is 27.

The square root of 222116661 is about 14903.5787983960. The cubic root of 222116661 is about 605.6109403517.

Adding to 222116661 its reverse (166611222), we get a palindrome (388727883).

The spelling of 222116661 in words is "two hundred twenty-two million, one hundred sixteen thousand, six hundred sixty-one".