1311918691 has 4 divisors (see below), whose sum is σ = 1342428472. Its totient is φ = 1281408912.

The previous prime is 1311918677. The next prime is 1311918701. The reversal of 1311918691 is 1968191131.

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

It is a cyclic number.

It is not a de Polignac number, because 1311918691 - 2¹⁵ = 1311885923 is a prime.

It is a super-2 number, since 2×1311918691² = 3442261303590306962, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1311918991) 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, 15254826 + ... + 15254911.

It is an arithmetic number, because the mean of its divisors is an integer number (335607118).

Almost surely, 2^1311918691 is an apocalyptic number.

1311918691 is a deficient number, since it is larger than the sum of its proper divisors (30509781).

1311918691 is an equidigital number, since it uses as much as digits as its factorization.

1311918691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30509780.

The product of its digits is 11664, while the sum is 40.

The square root of 1311918691 is about 36220.4181505404. The cubic root of 1311918691 is about 1094.7181195854.

The spelling of 1311918691 in words is "one billion, three hundred eleven million, nine hundred eighteen thousand, six hundred ninety-one".