13181820 has 96 divisors (see below), whose sum is σ = 40212480. Its totient is φ = 3214080.

The previous prime is 13181809. The next prime is 13181827. The reversal of 13181820 is 2818131.

13181820 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13181827) 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, 35154 + ... + 35526.

It is an arithmetic number, because the mean of its divisors is an integer number (418880).

Almost surely, 2^13181820 is an apocalyptic number.

13181820 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 13181820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20106240).

13181820 is an abundant number, since it is smaller than the sum of its proper divisors (27030660).

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

13181820 is a wasteful number, since it uses less digits than its factorization.

13181820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 435 (or 433 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 24.

The square root of 13181820 is about 3630.6776227035. The cubic root of 13181820 is about 236.2246018440.

Adding to 13181820 its reverse (2818131), we get a palindrome (15999951).

The spelling of 13181820 in words is "thirteen million, one hundred eighty-one thousand, eight hundred twenty".