243121213733 has 2 divisors, whose sum is σ = 243121213734. Its totient is φ = 243121213732.

The previous prime is 243121213729. The next prime is 243121213757. The reversal of 243121213733 is 337312121342.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 170039120164 + 73082093569 = 412358^2 + 270337^2 .

It is a cyclic number.

It is not a de Polignac number, because 243121213733 - 2² = 243121213729 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 243121213733.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243121213703) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121560606866 + 121560606867.

It is an arithmetic number, because the mean of its divisors is an integer number (121560606867).

Almost surely, 2^243121213733 is an apocalyptic number.

It is an amenable number.

243121213733 is a deficient number, since it is larger than the sum of its proper divisors (1).

243121213733 is an equidigital number, since it uses as much as digits as its factorization.

243121213733 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18144, while the sum is 32.

The spelling of 243121213733 in words is "two hundred forty-three billion, one hundred twenty-one million, two hundred thirteen thousand, seven hundred thirty-three".