12640438 has 4 divisors (see below), whose sum is σ = 18960660. Its totient is φ = 6320218.

The previous prime is 12640429. The next prime is 12640451. The reversal of 12640438 is 83404621.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3160108 + ... + 3160111.

It is an arithmetic number, because the mean of its divisors is an integer number (4740165).

Almost surely, 2^12640438 is an apocalyptic number.

12640438 is a deficient number, since it is larger than the sum of its proper divisors (6320222).

12640438 is an equidigital number, since it uses as much as digits as its factorization.

12640438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6320221.

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 12640438 is about 3555.3393649552. The cubic root of 12640438 is about 232.9453475064.

The spelling of 12640438 in words is "twelve million, six hundred forty thousand, four hundred thirty-eight".