1311666115 has 4 divisors (see below), whose sum is σ = 1573999344. Its totient is φ = 1049332888.

The previous prime is 1311666091. The next prime is 1311666157. The reversal of 1311666115 is 5116661131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5116661131 = 113 ⋅45280187.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1311666115 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 131166607 + ... + 131166616.

It is an arithmetic number, because the mean of its divisors is an integer number (393499836).

Almost surely, 2^1311666115 is an apocalyptic number.

1311666115 is a deficient number, since it is larger than the sum of its proper divisors (262333229).

1311666115 is an equidigital number, since it uses as much as digits as its factorization.

1311666115 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262333228.

The product of its digits is 3240, while the sum is 31.

The square root of 1311666115 is about 36216.9313305255. The cubic root of 1311666115 is about 1094.6478618598.

The spelling of 1311666115 in words is "one billion, three hundred eleven million, six hundred sixty-six thousand, one hundred fifteen".