13256640 has 84 divisors (see below), whose sum is σ = 45607224. Its totient is φ = 3534336.

The previous prime is 13256597. The next prime is 13256647. The reversal of 13256640 is 4665231.

13256640 is a `hidden beast` number, since 13 + 2 + 5 + 6 + 640 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13256647) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 579 + ... + 5181.

Almost surely, 2^13256640 is an apocalyptic number.

13256640 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 13256640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22803612).

13256640 is an abundant number, since it is smaller than the sum of its proper divisors (32350584).

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

13256640 is a wasteful number, since it uses less digits than its factorization.

13256640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4626 (or 4613 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 13256640 is about 3640.9669045461. The cubic root of 13256640 is about 236.6706957810.

The spelling of 13256640 in words is "thirteen million, two hundred fifty-six thousand, six hundred forty".