12640385 has 4 divisors (see below), whose sum is σ = 15168468. Its totient is φ = 10112304.

The previous prime is 12640373. The next prime is 12640393. The reversal of 12640385 is 58304621.

12640385 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 58304621 = 107 ⋅544903.

It can be written as a sum of positive squares in 2 ways, for example, as 1723969 + 10916416 = 1313^2 + 3304^2 .

It is a cyclic number.

It is not a de Polignac number, because 12640385 - 2¹⁸ = 12378241 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1264034 + ... + 1264043.

It is an arithmetic number, because the mean of its divisors is an integer number (3792117).

Almost surely, 2^12640385 is an apocalyptic number.

It is an amenable number.

12640385 is a deficient number, since it is larger than the sum of its proper divisors (2528083).

12640385 is an equidigital number, since it uses as much as digits as its factorization.

12640385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2528082.

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 12640385 is about 3555.3319113692. The cubic root of 12640385 is about 232.9450219343.

The spelling of 12640385 in words is "twelve million, six hundred forty thousand, three hundred eighty-five".