13656440 has 128 divisors (see below), whose sum is σ = 39398400. Its totient is φ = 4147200.

The previous prime is 13656439. The next prime is 13656443. The reversal of 13656440 is 4465631.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13656443) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 90365 + ... + 90515.

It is an arithmetic number, because the mean of its divisors is an integer number (307800).

Almost surely, 2^13656440 is an apocalyptic number.

13656440 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 13656440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19699200).

13656440 is an abundant number, since it is smaller than the sum of its proper divisors (25741960).

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

13656440 is a wasteful number, since it uses less digits than its factorization.

13656440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205 (or 201 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 13656440 is about 3695.4620820677. The cubic root of 13656440 is about 239.0263796796.

The spelling of 13656440 in words is "thirteen million, six hundred fifty-six thousand, four hundred forty".