243121355441 has 2 divisors, whose sum is σ = 243121355442. Its totient is φ = 243121355440.

The previous prime is 243121355429. The next prime is 243121355443. The reversal of 243121355441 is 144553121342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 222096355441 + 21025000000 = 471271^2 + 145000^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243121355441 is a prime.

Together with 243121355443, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (243121355443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121560677720 + 121560677721.

It is an arithmetic number, because the mean of its divisors is an integer number (121560677721).

Almost surely, 2^243121355441 is an apocalyptic number.

It is an amenable number.

243121355441 is a deficient number, since it is larger than the sum of its proper divisors (1).

243121355441 is an equidigital number, since it uses as much as digits as its factorization.

243121355441 is an evil number, because the sum of its binary digits is even.

The product of its digits is 57600, while the sum is 35.

Adding to 243121355441 its reverse (144553121342), we get a palindrome (387674476783).

The spelling of 243121355441 in words is "two hundred forty-three billion, one hundred twenty-one million, three hundred fifty-five thousand, four hundred forty-one".