12786661 has 4 divisors (see below), whose sum is σ = 12807072. Its totient is φ = 12766252.

The previous prime is 12786649. The next prime is 12786691. The reversal of 12786661 is 16668721.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 12786661 - 2¹¹ = 12784613 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12786661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12786611) 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, 9235 + ... + 10528.

It is an arithmetic number, because the mean of its divisors is an integer number (3201768).

Almost surely, 2^12786661 is an apocalyptic number.

It is an amenable number.

12786661 is a deficient number, since it is larger than the sum of its proper divisors (20411).

12786661 is an equidigital number, since it uses as much as digits as its factorization.

12786661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20410.

The product of its digits is 24192, while the sum is 37.

The square root of 12786661 is about 3575.8440961541. The cubic root of 12786661 is about 233.8401335798.

The spelling of 12786661 in words is "twelve million, seven hundred eighty-six thousand, six hundred sixty-one".