1266520319963 has 2 divisors, whose sum is σ = 1266520319964. Its totient is φ = 1266520319962.

The previous prime is 1266520319957. The next prime is 1266520320001. The reversal of 1266520319963 is 3699130256621.

It is a weak prime.

It is an emirp because it is prime and its reverse (3699130256621) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1266520319963 - 2²⁶ = 1266453211099 is a prime.

It is not a weakly prime, because it can be changed into another prime (1266520339963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 633260159981 + 633260159982.

It is an arithmetic number, because the mean of its divisors is an integer number (633260159982).

Almost surely, 2^{1266520319963} is an apocalyptic number.

1266520319963 is a deficient number, since it is larger than the sum of its proper divisors (1).

1266520319963 is an equidigital number, since it uses as much as digits as its factorization.

1266520319963 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3149280, while the sum is 53.

The spelling of 1266520319963 in words is "one trillion, two hundred sixty-six billion, five hundred twenty million, three hundred nineteen thousand, nine hundred sixty-three".