1243243455019 has 2 divisors, whose sum is σ = 1243243455020. Its totient is φ = 1243243455018.

The previous prime is 1243243455017. The next prime is 1243243455061. The reversal of 1243243455019 is 9105543423421.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1243243455019 - 2¹ = 1243243455017 is a prime.

It is a super-2 number, since 2×1243243455019² (a number of 25 digits) contains 22 as substring.

Together with 1243243455017, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1243243455017) 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, 621621727509 + 621621727510.

It is an arithmetic number, because the mean of its divisors is an integer number (621621727510).

Almost surely, 2^{1243243455019} is an apocalyptic number.

1243243455019 is a deficient number, since it is larger than the sum of its proper divisors (1).

1243243455019 is an equidigital number, since it uses as much as digits as its factorization.

1243243455019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 518400, while the sum is 43.

The spelling of 1243243455019 in words is "one trillion, two hundred forty-three billion, two hundred forty-three million, four hundred fifty-five thousand, nineteen".