12866640 has 40 divisors (see below), whose sum is σ = 39887328. Its totient is φ = 3431040.

The previous prime is 12866627. The next prime is 12866647. The reversal of 12866640 is 4666821.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12866647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26566 + ... + 27045.

Almost surely, 2^12866640 is an apocalyptic number.

12866640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12866640 is an abundant number, since it is smaller than the sum of its proper divisors (27020688).

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

12866640 is a wasteful number, since it uses less digits than its factorization.

12866640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53627 (or 53621 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 12866640 is about 3587.0098968361. The cubic root of 12866640 is about 234.3266677226.

The spelling of 12866640 in words is "twelve million, eight hundred sixty-six thousand, six hundred forty".