1243378275791 has 2 divisors, whose sum is σ = 1243378275792. Its totient is φ = 1243378275790.

The previous prime is 1243378275787. The next prime is 1243378275889. The reversal of 1243378275791 is 1975728733421.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1243378275791 - 2² = 1243378275787 is a prime.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1243378275791.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1243378275721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621689137895 + 621689137896.

It is an arithmetic number, because the mean of its divisors is an integer number (621689137896).

Almost surely, 2^{1243378275791} is an apocalyptic number.

1243378275791 is a deficient number, since it is larger than the sum of its proper divisors (1).

1243378275791 is an equidigital number, since it uses as much as digits as its factorization.

1243378275791 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17781120, while the sum is 59.

The spelling of 1243378275791 in words is "one trillion, two hundred forty-three billion, three hundred seventy-eight million, two hundred seventy-five thousand, seven hundred ninety-one".