12686440 has 64 divisors (see below), whose sum is σ = 31772160. Its totient is φ = 4527360.

The previous prime is 12686431. The next prime is 12686441. The reversal of 12686440 is 4468621.

12686440 = T₅₉₂ + T₅₉₃ + ... + T₆₅₆.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is not an unprimeable number, because it can be changed into a prime (12686441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15727 + ... + 16513.

It is an arithmetic number, because the mean of its divisors is an integer number (496440).

Almost surely, 2^12686440 is an apocalyptic number.

12686440 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 12686440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15886080).

12686440 is an abundant number, since it is smaller than the sum of its proper divisors (19085720).

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

12686440 is a wasteful number, since it uses less digits than its factorization.

12686440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 842 (or 838 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 12686440 is about 3561.8029142556. The cubic root of 12686440 is about 233.2275892734.

The spelling of 12686440 in words is "twelve million, six hundred eighty-six thousand, four hundred forty".