1268819564381 has 4 divisors (see below), whose sum is σ = 1268823213852. Its totient is φ = 1268815914912.

The previous prime is 1268819564357. The next prime is 1268819564423. The reversal of 1268819564381 is 1834659188621.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 663393960100 + 605425604281 = 814490^2 + 778091^2 .

It is a cyclic number.

It is not a de Polignac number, because 1268819564381 - 2³⁰ = 1267745822557 is a prime.

It is a super-2 number, since 2×1268819564381² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1268819564351) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1240976 + ... + 2019321.

It is an arithmetic number, because the mean of its divisors is an integer number (317205803463).

Almost surely, 2^{1268819564381} is an apocalyptic number.

It is an amenable number.

1268819564381 is a deficient number, since it is larger than the sum of its proper divisors (3649471).

1268819564381 is an equidigital number, since it uses as much as digits as its factorization.

1268819564381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3649470.

The product of its digits is 19906560, while the sum is 62.

The spelling of 1268819564381 in words is "one trillion, two hundred sixty-eight billion, eight hundred nineteen million, five hundred sixty-four thousand, three hundred eighty-one".