1311045116261 has 4 divisors (see below), whose sum is σ = 1317838096332. Its totient is φ = 1304252136192.

The previous prime is 1311045116243. The next prime is 1311045116291. The reversal of 1311045116261 is 1626115401131.

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 691666672225 + 619378444036 = 831665^2 + 787006^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1311045116261 is a prime.

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 (1311045116221) 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, 3396489746 + ... + 3396490131.

It is an arithmetic number, because the mean of its divisors is an integer number (329459524083).

Almost surely, 2^{1311045116261} is an apocalyptic number.

It is an amenable number.

1311045116261 is a deficient number, since it is larger than the sum of its proper divisors (6792980071).

1311045116261 is an equidigital number, since it uses as much as digits as its factorization.

1311045116261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6792980070.

The product of its (nonzero) digits is 4320, while the sum is 32.

The spelling of 1311045116261 in words is "one trillion, three hundred eleven billion, forty-five million, one hundred sixteen thousand, two hundred sixty-one".