13256605440 has 864 divisors, whose sum is σ = 53997705216. Its totient is φ = 2972712960.

The previous prime is 13256605379. The next prime is 13256605441. The reversal of 13256605440 is 4450665231.

13256605440 is a `hidden beast` number, since 1 + 3 + 2 + 5 + 6 + 605 + 4 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 13256605395 and 13256605404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13256605441) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 104382657 + ... + 104382783.

It is an arithmetic number, because the mean of its divisors is an integer number (62497344).

Almost surely, 2^13256605440 is an apocalyptic number.

13256605440 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 13256605440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26998852608).

13256605440 is an abundant number, since it is smaller than the sum of its proper divisors (40741099776).

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

13256605440 is a wasteful number, since it uses less digits than its factorization.

13256605440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225 (or 208 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 36.

The spelling of 13256605440 in words is "thirteen billion, two hundred fifty-six million, six hundred five thousand, four hundred forty".