221133221 has 4 divisors (see below), whose sum is σ = 221163744. Its totient is φ = 221102700.

The previous prime is 221133193. The next prime is 221133233. The reversal of 221133221 is 122331122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 122331122 = 2 ⋅61165561.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221133221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221133221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221133251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2486 + ... + 21176.

It is an arithmetic number, because the mean of its divisors is an integer number (55290936).

Almost surely, 2^221133221 is an apocalyptic number.

It is an amenable number.

221133221 is a deficient number, since it is larger than the sum of its proper divisors (30523).

221133221 is a wasteful number, since it uses less digits than its factorization.

221133221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30522.

The product of its digits is 144, while the sum is 17.

The square root of 221133221 is about 14870.5487793827. The cubic root of 221133221 is about 604.7158203648.

Adding to 221133221 its reverse (122331122), we get a palindrome (343464343).

The spelling of 221133221 in words is "two hundred twenty-one million, one hundred thirty-three thousand, two hundred twenty-one".