13131220 has 12 divisors (see below), whose sum is σ = 27575604. Its totient is φ = 5252480.

The previous prime is 13131203. The next prime is 13131233. The reversal of 13131220 is 2213131.

13131220 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 6140484 + 6990736 = 2478^2 + 2644^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 13131220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 328261 + ... + 328300.

It is an arithmetic number, because the mean of its divisors is an integer number (2297967).

Almost surely, 2^13131220 is an apocalyptic number.

13131220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13131220 is an abundant number, since it is smaller than the sum of its proper divisors (14444384).

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

13131220 is a wasteful number, since it uses less digits than its factorization.

13131220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 656570 (or 656568 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 13131220 is about 3623.7025264224. The cubic root of 13131220 is about 235.9219554252.

Adding to 13131220 its reverse (2213131), we get a palindrome (15344351).

The spelling of 13131220 in words is "thirteen million, one hundred thirty-one thousand, two hundred twenty".