1281665665019 has 2 divisors, whose sum is σ = 1281665665020. Its totient is φ = 1281665665018.

The previous prime is 1281665664991. The next prime is 1281665665039. The reversal of 1281665665019 is 9105665661821.

It is a strong prime.

It is an emirp because it is prime and its reverse (9105665661821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1281665665019 - 2¹⁶ = 1281665599483 is a prime.

It is a super-2 number, since 2×1281665665019² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1281665665039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 640832832509 + 640832832510.

It is an arithmetic number, because the mean of its divisors is an integer number (640832832510).

Almost surely, 2^{1281665665019} is an apocalyptic number.

1281665665019 is a deficient number, since it is larger than the sum of its proper divisors (1).

1281665665019 is an equidigital number, since it uses as much as digits as its factorization.

1281665665019 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4665600, while the sum is 56.

The spelling of 1281665665019 in words is "one trillion, two hundred eighty-one billion, six hundred sixty-five million, six hundred sixty-five thousand, nineteen".