12791665 has 4 divisors (see below), whose sum is σ = 15350004. Its totient is φ = 10233328.

The previous prime is 12791659. The next prime is 12791671. The reversal of 12791665 is 56619721.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56619721 = 23 ⋅2461727.

It is an interprime number because it is at equal distance from previous prime (12791659) and next prime (12791671).

It can be written as a sum of positive squares in 2 ways, for example, as 2862864 + 9928801 = 1692^2 + 3151^2 .

It is a cyclic number.

It is not a de Polignac number, because 12791665 - 2¹¹ = 12789617 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1279162 + ... + 1279171.

It is an arithmetic number, because the mean of its divisors is an integer number (3837501).

Almost surely, 2^12791665 is an apocalyptic number.

It is an amenable number.

12791665 is a deficient number, since it is larger than the sum of its proper divisors (2558339).

12791665 is an equidigital number, since it uses as much as digits as its factorization.

12791665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2558338.

The product of its digits is 22680, while the sum is 37.

The square root of 12791665 is about 3576.5437226462. The cubic root of 12791665 is about 233.8706336824.

It can be divided in two parts, 12791 and 665, that added together give a square (13456 = 116²).

The spelling of 12791665 in words is "twelve million, seven hundred ninety-one thousand, six hundred sixty-five".