11031231220 has 48 divisors (see below), whose sum is σ = 23832860688. Its totient is φ = 4286320640.

The previous prime is 11031231217. The next prime is 11031231221. The reversal of 11031231220 is 2213213011.

It can be written as a sum of positive squares in 8 ways, for example, as 4972788324 + 6058442896 = 70518^2 + 77836^2 .

It is a junction number, because it is equal to n+sod(n) for n = 11031231194 and 11031231203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11031231221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 162192 + ... + 219928.

It is an arithmetic number, because the mean of its divisors is an integer number (496517931).

Almost surely, 2^11031231220 is an apocalyptic number.

11031231220 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 11031231220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11916430344).

11031231220 is an abundant number, since it is smaller than the sum of its proper divisors (12801629468).

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

11031231220 is a wasteful number, since it uses less digits than its factorization.

11031231220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58020 (or 58018 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 11031231220 its reverse (2213213011), we get a palindrome (13244444231).

The spelling of 11031231220 in words is "eleven billion, thirty-one million, two hundred thirty-one thousand, two hundred twenty".