221443243 has 4 divisors (see below), whose sum is σ = 253078000. Its totient is φ = 189808488.

The previous prime is 221443171. The next prime is 221443289. The reversal of 221443243 is 342344122.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 221443243 - 2¹³ = 221435051 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221443843) 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, 15817368 + ... + 15817381.

It is an arithmetic number, because the mean of its divisors is an integer number (63269500).

Almost surely, 2^221443243 is an apocalyptic number.

221443243 is a deficient number, since it is larger than the sum of its proper divisors (31634757).

221443243 is an equidigital number, since it uses as much as digits as its factorization.

221443243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31634756.

The product of its digits is 4608, while the sum is 25.

The square root of 221443243 is about 14880.9691552667. The cubic root of 221443243 is about 604.9982860867.

Adding to 221443243 its reverse (342344122), we get a palindrome (563787365).

The spelling of 221443243 in words is "two hundred twenty-one million, four hundred forty-three thousand, two hundred forty-three".