221042243 has 4 divisors (see below), whose sum is σ = 221072520. Its totient is φ = 221011968.

The previous prime is 221042221. The next prime is 221042281. The reversal of 221042243 is 342240122.

221042243 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 221042243 - 2¹⁸ = 220780099 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221042203) 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, 3296 + ... + 21282.

It is an arithmetic number, because the mean of its divisors is an integer number (55268130).

Almost surely, 2^221042243 is an apocalyptic number.

221042243 is a deficient number, since it is larger than the sum of its proper divisors (30277).

221042243 is a wasteful number, since it uses less digits than its factorization.

221042243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30276.

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 221042243 is about 14867.4894652729. The cubic root of 221042243 is about 604.6328788357.

Adding to 221042243 its reverse (342240122), we get a palindrome (563282365).

The spelling of 221042243 in words is "two hundred twenty-one million, forty-two thousand, two hundred forty-three".