13643840 has 56 divisors (see below), whose sum is σ = 37136832. Its totient is φ = 4677120.

The previous prime is 13643837. The next prime is 13643863. The reversal of 13643840 is 4834631.

It is a tau number, because it is divible by the number of its divisors (56).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 806 + ... + 5285.

Almost surely, 2^13643840 is an apocalyptic number.

13643840 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 13643840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18568416).

13643840 is an abundant number, since it is smaller than the sum of its proper divisors (23492992).

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

13643840 is an equidigital number, since it uses as much as digits as its factorization.

13643840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6115 (or 6105 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 29.

The square root of 13643840 is about 3693.7568950866. The cubic root of 13643840 is about 238.9528451638.

The spelling of 13643840 in words is "thirteen million, six hundred forty-three thousand, eight hundred forty".