12766391 has 4 divisors (see below), whose sum is σ = 13926984. Its totient is φ = 11605800.

The previous prime is 12766373. The next prime is 12766393. The reversal of 12766391 is 19366721.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12766391 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12766393) by changing a digit.

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, 580280 + ... + 580301.

It is an arithmetic number, because the mean of its divisors is an integer number (3481746).

Almost surely, 2^12766391 is an apocalyptic number.

12766391 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

12766391 is a deficient number, since it is larger than the sum of its proper divisors (1160593).

12766391 is a wasteful number, since it uses less digits than its factorization.

12766391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1160592.

The product of its digits is 13608, while the sum is 35.

The square root of 12766391 is about 3573.0086761719. The cubic root of 12766391 is about 233.7165035361.

It can be divided in two parts, 1276 and 6391, that added together give a palindrome (7667).

The spelling of 12766391 in words is "twelve million, seven hundred sixty-six thousand, three hundred ninety-one".