221544213 has 16 divisors (see below), whose sum is σ = 329742336. Its totient is φ = 131145840.

The previous prime is 221544209. The next prime is 221544223. The reversal of 221544213 is 312445122.

It is not a de Polignac number, because 221544213 - 2² = 221544209 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221544223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 76645 + ... + 79482.

It is an arithmetic number, because the mean of its divisors is an integer number (20608896).

Almost surely, 2^221544213 is an apocalyptic number.

It is an amenable number.

221544213 is a deficient number, since it is larger than the sum of its proper divisors (108198123).

221544213 is a wasteful number, since it uses less digits than its factorization.

221544213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156184.

The product of its digits is 1920, while the sum is 24.

The square root of 221544213 is about 14884.3613568067. The cubic root of 221544213 is about 605.0902244604.

Adding to 221544213 its reverse (312445122), we get a palindrome (533989335).

Subtracting 221544213 from its reverse (312445122), we obtain a palindrome (90900909).

The spelling of 221544213 in words is "two hundred twenty-one million, five hundred forty-four thousand, two hundred thirteen".