243636121709 has 2 divisors, whose sum is σ = 243636121710. Its totient is φ = 243636121708.

The previous prime is 243636121607. The next prime is 243636121769. The reversal of 243636121709 is 907121636342.

243636121709 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., 229491776809 + 14144344900 = 479053^2 + 118930^2 .

It is a cyclic number.

It is not a de Polignac number, because 243636121709 - 2¹⁶ = 243636056173 is a prime.

It is a super-2 number, since 2×243636121709² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 243636121709.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243636121769) 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, 121818060854 + 121818060855.

It is an arithmetic number, because the mean of its divisors is an integer number (121818060855).

Almost surely, 2^243636121709 is an apocalyptic number.

It is an amenable number.

243636121709 is a deficient number, since it is larger than the sum of its proper divisors (1).

243636121709 is an equidigital number, since it uses as much as digits as its factorization.

243636121709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 326592, while the sum is 44.

The spelling of 243636121709 in words is "two hundred forty-three billion, six hundred thirty-six million, one hundred twenty-one thousand, seven hundred nine".