13640256 has 168 divisors, whose sum is σ = 47548800. Its totient is φ = 3649536.

The previous prime is 13640213. The next prime is 13640257. The reversal of 13640256 is 65204631.

13640256 is a `hidden beast` number, since 13 + 640 + 2 + 5 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (168).

It is not an unprimeable number, because it can be changed into a prime (13640257) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 68445 + ... + 68643.

Almost surely, 2^13640256 is an apocalyptic number.

13640256 is a gapful number since it is divisible by the number (16) 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 13640256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23774400).

13640256 is an abundant number, since it is smaller than the sum of its proper divisors (33908544).

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

13640256 is a wasteful number, since it uses less digits than its factorization.

13640256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241 (or 228 counting only the distinct ones).

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

The square root of 13640256 is about 3693.2717203044. The cubic root of 13640256 is about 238.9319204096.

Adding to 13640256 its reverse (65204631), we get a palindrome (78844887).

The spelling of 13640256 in words is "thirteen million, six hundred forty thousand, two hundred fifty-six".