243302021 has 4 divisors (see below), whose sum is σ = 243346572. Its totient is φ = 243257472.

The previous prime is 243301997. The next prime is 243302023. The reversal of 243302021 is 120203342.

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

It can be written as a sum of positive squares in 2 ways, for example, as 93508900 + 149793121 = 9670^2 + 12239^2 .

It is a cyclic number.

It is not a de Polignac number, because 243302021 - 2¹⁰ = 243300997 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243302023) 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, 12716 + ... + 25461.

It is an arithmetic number, because the mean of its divisors is an integer number (60836643).

Almost surely, 2^243302021 is an apocalyptic number.

It is an amenable number.

243302021 is a deficient number, since it is larger than the sum of its proper divisors (44551).

243302021 is an equidigital number, since it uses as much as digits as its factorization.

243302021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44550.

The product of its (nonzero) digits is 288, while the sum is 17.

The square root of 243302021 is about 15598.1415880226. The cubic root of 243302021 is about 624.2835703328.

Adding to 243302021 its reverse (120203342), we get a palindrome (363505363).

The spelling of 243302021 in words is "two hundred forty-three million, three hundred two thousand, twenty-one".