13021331220 has 144 divisors (see below), whose sum is σ = 41997363408. Its totient is φ = 3254353920.

The previous prime is 13021331177. The next prime is 13021331221. The reversal of 13021331220 is 2213312031.

It can be written as a sum of positive squares in 8 ways, for example, as 695556 + 13020635664 = 834^2 + 114108^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 13021331193 and 13021331202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13021331221) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 728632 + ... + 746288.

It is an arithmetic number, because the mean of its divisors is an integer number (291648357).

Almost surely, 2^13021331220 is an apocalyptic number.

13021331220 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 13021331220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20998681704).

13021331220 is an abundant number, since it is smaller than the sum of its proper divisors (28976032188).

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

13021331220 is a wasteful number, since it uses less digits than its factorization.

13021331220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17930 (or 17925 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 13021331220 its reverse (2213312031), we get a palindrome (15234643251).

The spelling of 13021331220 in words is "thirteen billion, twenty-one million, three hundred thirty-one thousand, two hundred twenty".