11013121220 has 96 divisors (see below), whose sum is σ = 25015804128. Its totient is φ = 4057178112.

The previous prime is 11013121201. The next prime is 11013121241. The reversal of 11013121220 is 2212131011.

It can be written as a sum of positive squares in 16 ways, for example, as 1396965376 + 9616155844 = 37376^2 + 98062^2 .

It is a junction number, because it is equal to n+sod(n) for n = 11013121195 and 11013121204.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11045762 + ... + 11046758.

It is an arithmetic number, because the mean of its divisors is an integer number (260581293).

Almost surely, 2^11013121220 is an apocalyptic number.

11013121220 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 11013121220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12507902064).

11013121220 is an abundant number, since it is smaller than the sum of its proper divisors (14002682908).

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

11013121220 is a wasteful number, since it uses less digits than its factorization.

11013121220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1689 (or 1687 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 11013121220 its reverse (2212131011), we get a palindrome (13225252231).

The spelling of 11013121220 in words is "eleven billion, thirteen million, one hundred twenty-one thousand, two hundred twenty".