12638840 has 32 divisors (see below), whose sum is σ = 28712880. Its totient is φ = 5006592.

The previous prime is 12638839. The next prime is 12638849. The reversal of 12638840 is 4883621.

It is a junction number, because it is equal to n+sod(n) for n = 12638797 and 12638806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12638849) 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, 2804 + ... + 5756.

Almost surely, 2^12638840 is an apocalyptic number.

12638840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12638840 is an abundant number, since it is smaller than the sum of its proper divisors (16074040).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12638840 is a wasteful number, since it uses less digits than its factorization.

12638840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3071 (or 3067 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 12638840 is about 3555.1146254376. The cubic root of 12638840 is about 232.9355308014.

The spelling of 12638840 in words is "twelve million, six hundred thirty-eight thousand, eight hundred forty".