12726661 has 4 divisors (see below), whose sum is σ = 12742272. Its totient is φ = 12711052.

The previous prime is 12726643. The next prime is 12726673. The reversal of 12726661 is 16662721.

It is a happy number.

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 12726661 - 2⁷ = 12726533 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 (12726611) 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, 6511 + ... + 8236.

It is an arithmetic number, because the mean of its divisors is an integer number (3185568).

Almost surely, 2^12726661 is an apocalyptic number.

It is an amenable number.

12726661 is a deficient number, since it is larger than the sum of its proper divisors (15611).

12726661 is an equidigital number, since it uses as much as digits as its factorization.

12726661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15610.

The product of its digits is 6048, while the sum is 31.

The square root of 12726661 is about 3567.4446036344. Note that the first 3 decimals coincide. The cubic root of 12726661 is about 233.4738036263.

The spelling of 12726661 in words is "twelve million, seven hundred twenty-six thousand, six hundred sixty-one".