243836568421 has 2 divisors, whose sum is σ = 243836568422. Its totient is φ = 243836568420.

The previous prime is 243836568407. The next prime is 243836568427. The reversal of 243836568421 is 124865638342.

243836568421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 155404677796 + 88431890625 = 394214^2 + 297375^2 .

It is a cyclic number.

It is not a de Polignac number, because 243836568421 - 2¹³ = 243836560229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243836568427) 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 as a sum of consecutive naturals, namely, 121918284210 + 121918284211.

It is an arithmetic number, because the mean of its divisors is an integer number (121918284211).

Almost surely, 2^243836568421 is an apocalyptic number.

It is an amenable number.

243836568421 is a deficient number, since it is larger than the sum of its proper divisors (1).

243836568421 is an equidigital number, since it uses as much as digits as its factorization.

243836568421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6635520, while the sum is 52.

The spelling of 243836568421 in words is "two hundred forty-three billion, eight hundred thirty-six million, five hundred sixty-eight thousand, four hundred twenty-one".