243203351491 has 2 divisors, whose sum is σ = 243203351492. Its totient is φ = 243203351490.

The previous prime is 243203351473. The next prime is 243203351557. The reversal of 243203351491 is 194153302342.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 243203351491 - 2⁹ = 243203350979 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 243203351491.

It is not a weakly prime, because it can be changed into another prime (243203351441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121601675745 + 121601675746.

It is an arithmetic number, because the mean of its divisors is an integer number (121601675746).

Almost surely, 2^243203351491 is an apocalyptic number.

243203351491 is a deficient number, since it is larger than the sum of its proper divisors (1).

243203351491 is an equidigital number, since it uses as much as digits as its factorization.

243203351491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 77760, while the sum is 37.

The spelling of 243203351491 in words is "two hundred forty-three billion, two hundred three million, three hundred fifty-one thousand, four hundred ninety-one".