243056221 has 16 divisors (see below), whose sum is σ = 255752640. Its totient is φ = 230688640.

The previous prime is 243056179. The next prime is 243056237. The reversal of 243056221 is 122650342.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243056221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243056321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 520230 + ... + 520696.

It is an arithmetic number, because the mean of its divisors is an integer number (15984540).

Almost surely, 2^243056221 is an apocalyptic number.

It is an amenable number.

243056221 is a deficient number, since it is larger than the sum of its proper divisors (12696419).

243056221 is a wasteful number, since it uses less digits than its factorization.

243056221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 764.

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

The square root of 243056221 is about 15590.2604532445. The cubic root of 243056221 is about 624.0732684690.

The spelling of 243056221 in words is "two hundred forty-three million, fifty-six thousand, two hundred twenty-one".