13211121220 has 72 divisors (see below), whose sum is σ = 30664257624. Its totient is φ = 4777344000.

The previous prime is 13211121197. The next prime is 13211121221. The reversal of 13211121220 is 2212111231.

It can be written as a sum of positive squares in 4 ways, for example, as 264322564 + 12946798656 = 16258^2 + 113784^2 .

It is a junction number, because it is equal to n+sod(n) for n = 13211121194 and 13211121203.

It is not an unprimeable number, because it can be changed into a prime (13211121221) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 422940 + ... + 453100.

It is an arithmetic number, because the mean of its divisors is an integer number (425892467).

Almost surely, 2^13211121220 is an apocalyptic number.

13211121220 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 13211121220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15332128812).

13211121220 is an abundant number, since it is smaller than the sum of its proper divisors (17453136404).

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

13211121220 is a wasteful number, since it uses less digits than its factorization.

13211121220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30373 (or 30360 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 13211121220 its reverse (2212111231), we get a palindrome (15423232451).

It can be divided in two parts, 13211 and 121220, that added together give a palindrome (134431).

The spelling of 13211121220 in words is "thirteen billion, two hundred eleven million, one hundred twenty-one thousand, two hundred twenty".