221513443 has 4 divisors (see below), whose sum is σ = 221729328. Its totient is φ = 221297560.

The previous prime is 221513401. The next prime is 221513449. The reversal of 221513443 is 344315122.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221513443 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221513449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106396 + ... + 108457.

It is an arithmetic number, because the mean of its divisors is an integer number (55432332).

Almost surely, 2^221513443 is an apocalyptic number.

221513443 is a deficient number, since it is larger than the sum of its proper divisors (215885).

221513443 is a wasteful number, since it uses less digits than its factorization.

221513443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215884.

The product of its digits is 2880, while the sum is 25.

The square root of 221513443 is about 14883.3276857025. The cubic root of 221513443 is about 605.0622097540.

Adding to 221513443 its reverse (344315122), we get a palindrome (565828565).

The spelling of 221513443 in words is "two hundred twenty-one million, five hundred thirteen thousand, four hundred forty-three".