12663421 has 4 divisors (see below), whose sum is σ = 12673692. Its totient is φ = 12653152.

The previous prime is 12663403. The next prime is 12663433. The reversal of 12663421 is 12436621.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 12040900 + 622521 = 3470^2 + 789^2 .

It is a cyclic number.

It is not a de Polignac number, because 12663421 - 2⁵ = 12663389 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 (12663451) 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, 2986 + ... + 5851.

It is an arithmetic number, because the mean of its divisors is an integer number (3168423).

Almost surely, 2^12663421 is an apocalyptic number.

It is an amenable number.

12663421 is a deficient number, since it is larger than the sum of its proper divisors (10271).

12663421 is an equidigital number, since it uses as much as digits as its factorization.

12663421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10270.

The product of its digits is 1728, while the sum is 25.

The square root of 12663421 is about 3558.5700779948. The cubic root of 12663421 is about 233.0864433931.

The spelling of 12663421 in words is "twelve million, six hundred sixty-three thousand, four hundred twenty-one".