12638809 has 8 divisors (see below), whose sum is σ = 13212360. Its totient is φ = 12074496.

The previous prime is 12638807. The next prime is 12638827. The reversal of 12638809 is 90883621.

It can be written as a sum of positive squares in 4 ways, for example, as 5774409 + 6864400 = 2403^2 + 2620^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12638809 - 2¹ = 12638807 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12638807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 567 + ... + 5059.

It is an arithmetic number, because the mean of its divisors is an integer number (1651545).

Almost surely, 2^12638809 is an apocalyptic number.

It is an amenable number.

12638809 is a deficient number, since it is larger than the sum of its proper divisors (573551).

12638809 is an equidigital number, since it uses as much as digits as its factorization.

12638809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4619.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 12638809 is about 3555.1102655192. The cubic root of 12638809 is about 232.9353403565.

The spelling of 12638809 in words is "twelve million, six hundred thirty-eight thousand, eight hundred nine".