221343213 has 64 divisors (see below), whose sum is σ = 395297280. Its totient is φ = 106831872.

The previous prime is 221343173. The next prime is 221343251. The reversal of 221343213 is 312343122.

It is not a de Polignac number, because 221343213 - 2⁶ = 221343149 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 221343213.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221343253) 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 63 ways as a sum of consecutive naturals, for example, 171073 + ... + 172361.

It is an arithmetic number, because the mean of its divisors is an integer number (6176520).

Almost surely, 2^221343213 is an apocalyptic number.

It is an amenable number.

221343213 is a deficient number, since it is larger than the sum of its proper divisors (173954067).

221343213 is a wasteful number, since it uses less digits than its factorization.

221343213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1366.

The product of its digits is 864, while the sum is 21.

The square root of 221343213 is about 14877.6077714127. The cubic root of 221343213 is about 604.9071760693.

Adding to 221343213 its reverse (312343122), we get a palindrome (533686335).

Subtracting 221343213 from its reverse (312343122), we obtain a palindrome (90999909).

The spelling of 221343213 in words is "two hundred twenty-one million, three hundred forty-three thousand, two hundred thirteen".