12640 has 24 divisors (see below), whose sum is σ = 30240. Its totient is φ = 4992.

The previous prime is 12637. The next prime is 12641. The reversal of 12640 is 4621.

It is a nialpdrome in base 11.

It is a self number, because there is not a number n which added to its sum of digits gives 12640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121 + ... + 199.

It is an arithmetic number, because the mean of its divisors is an integer number (1260).

2¹²⁶⁴⁰ is an apocalyptic number.

12640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15120).

12640 is an abundant number, since it is smaller than the sum of its proper divisors (17600).

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

12640 is an equidigital number, since it uses as much as digits as its factorization.

12640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94 (or 86 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 12640 is about 112.4277545804. The cubic root of 12640 is about 23.2942656902.

The spelling of 12640 in words is "twelve thousand, six hundred forty".