243202021 has 2 divisors, whose sum is σ = 243202022. Its totient is φ = 243202020.

The previous prime is 243202007. The next prime is 243202039. The reversal of 243202021 is 120202342.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 213890625 + 29311396 = 14625^2 + 5414^2 .

It is a cyclic number.

It is not a de Polignac number, because 243202021 - 2⁹ = 243201509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 243201986 and 243202004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243202081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121601010 + 121601011.

It is an arithmetic number, because the mean of its divisors is an integer number (121601011).

Almost surely, 2^243202021 is an apocalyptic number.

It is an amenable number.

243202021 is a deficient number, since it is larger than the sum of its proper divisors (1).

243202021 is an equidigital number, since it uses as much as digits as its factorization.

243202021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 243202021 is about 15594.9357485050. The cubic root of 243202021 is about 624.1980293090.

Adding to 243202021 its reverse (120202342), we get a palindrome (363404363).

The spelling of 243202021 in words is "two hundred forty-three million, two hundred two thousand, twenty-one".