243121243 has 2 divisors, whose sum is σ = 243121244. Its totient is φ = 243121242.

The previous prime is 243121231. The next prime is 243121259. The reversal of 243121243 is 342121342.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243121243 is a prime.

It is not a weakly prime, because it can be changed into another prime (243121213) 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, 121560621 + 121560622.

It is an arithmetic number, because the mean of its divisors is an integer number (121560622).

Almost surely, 2^243121243 is an apocalyptic number.

243121243 is a deficient number, since it is larger than the sum of its proper divisors (1).

243121243 is an equidigital number, since it uses as much as digits as its factorization.

243121243 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1152, while the sum is 22.

The square root of 243121243 is about 15592.3456541984. The cubic root of 243121243 is about 624.1289138583.

Adding to 243121243 its reverse (342121342), we get a palindrome (585242585).

Subtracting 243121243 from its reverse (342121342), we obtain a palindrome (99000099).

The spelling of 243121243 in words is "two hundred forty-three million, one hundred twenty-one thousand, two hundred forty-three".