243121213009 has 2 divisors, whose sum is σ = 243121213010. Its totient is φ = 243121213008.

The previous prime is 243121212989. The next prime is 243121213021. The reversal of 243121213009 is 900312121342.

It is a happy number.

243121213009 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., 184328542225 + 58792670784 = 429335^2 + 242472^2 .

It is a cyclic number.

It is not a de Polignac number, because 243121213009 - 2⁷ = 243121212881 is a prime.

It is not a weakly prime, because it can be changed into another prime (243121213609) 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, 121560606504 + 121560606505.

It is an arithmetic number, because the mean of its divisors is an integer number (121560606505).

Almost surely, 2^243121213009 is an apocalyptic number.

It is an amenable number.

243121213009 is a deficient number, since it is larger than the sum of its proper divisors (1).

243121213009 is an equidigital number, since it uses as much as digits as its factorization.

243121213009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 28.

It can be divided in two parts, 24312 and 1213009, that added together give a palindrome (1237321).

The spelling of 243121213009 in words is "two hundred forty-three billion, one hundred twenty-one million, two hundred thirteen thousand, nine".