221918833 has 8 divisors (see below), whose sum is σ = 235116648. Its totient is φ = 208737024.

The previous prime is 221918797. The next prime is 221918857. The reversal of 221918833 is 338819122.

It can be written as a sum of positive squares in 4 ways, for example, as 10419984 + 211498849 = 3228^2 + 14543^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 221918833 - 2²¹ = 219821681 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221918792 and 221918801.

It is not an unprimeable number, because it can be changed into a prime (221918033) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36135 + ... + 41827.

It is an arithmetic number, because the mean of its divisors is an integer number (29389581).

Almost surely, 2^221918833 is an apocalyptic number.

It is an amenable number.

221918833 is a deficient number, since it is larger than the sum of its proper divisors (13197815).

221918833 is a wasteful number, since it uses less digits than its factorization.

221918833 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8003.

The product of its digits is 20736, while the sum is 37.

The square root of 221918833 is about 14896.9403905634. The cubic root of 221918833 is about 605.4310913378.

The spelling of 221918833 in words is "two hundred twenty-one million, nine hundred eighteen thousand, eight hundred thirty-three".