1366781236669 has 2 divisors, whose sum is σ = 1366781236670. Its totient is φ = 1366781236668.

The previous prime is 1366781236637. The next prime is 1366781236673. The reversal of 1366781236669 is 9666321876631.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1334475488025 + 32305748644 = 1155195^2 + 179738^2 .

It is a cyclic number.

It is not a de Polignac number, because 1366781236669 - 2⁵ = 1366781236637 is a prime.

It is a super-2 number, since 2×1366781236669² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1366781236669.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1366781239669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 683390618334 + 683390618335.

It is an arithmetic number, because the mean of its divisors is an integer number (683390618335).

Almost surely, 2^{1366781236669} is an apocalyptic number.

It is an amenable number.

1366781236669 is a deficient number, since it is larger than the sum of its proper divisors (1).

1366781236669 is an equidigital number, since it uses as much as digits as its factorization.

1366781236669 is an evil number, because the sum of its binary digits is even.

The product of its digits is 70543872, while the sum is 64.

The spelling of 1366781236669 in words is "one trillion, three hundred sixty-six billion, seven hundred eighty-one million, two hundred thirty-six thousand, six hundred sixty-nine".