221668311 has 16 divisors (see below), whose sum is σ = 302914304. Its totient is φ = 144111744.

The previous prime is 221668261. The next prime is 221668351. The reversal of 221668311 is 113866122.

It is not a de Polignac number, because 221668311 - 2⁶ = 221668247 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221668351) 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 15 ways as a sum of consecutive naturals, for example, 123855 + ... + 125631.

It is an arithmetic number, because the mean of its divisors is an integer number (18932144).

Almost surely, 2^221668311 is an apocalyptic number.

221668311 is a deficient number, since it is larger than the sum of its proper divisors (81245993).

221668311 is a wasteful number, since it uses less digits than its factorization.

221668311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2790.

The product of its digits is 3456, while the sum is 30.

The square root of 221668311 is about 14888.5295110028. The cubic root of 221668311 is about 605.2031838096.

The spelling of 221668311 in words is "two hundred twenty-one million, six hundred sixty-eight thousand, three hundred eleven".