13688820 has 72 divisors (see below), whose sum is σ = 41952456. Its totient is φ = 3612672.

The previous prime is 13688819. The next prime is 13688863. The reversal of 13688820 is 2888631.

It can be written as a sum of positive squares in 4 ways, for example, as 116964 + 13571856 = 342^2 + 3684^2 .

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20004 + ... + 20676.

It is an arithmetic number, because the mean of its divisors is an integer number (582673).

Almost surely, 2^13688820 is an apocalyptic number.

13688820 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 13688820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20976228).

13688820 is an abundant number, since it is smaller than the sum of its proper divisors (28263636).

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

13688820 is a wasteful number, since it uses less digits than its factorization.

13688820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 801 (or 796 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 13688820 is about 3699.8405371043. The cubic root of 13688820 is about 239.2151444720.

The spelling of 13688820 in words is "thirteen million, six hundred eighty-eight thousand, eight hundred twenty".