11131121220 has 96 divisors (see below), whose sum is σ = 31450301568. Its totient is φ = 2941412352.

The previous prime is 11131121213. The next prime is 11131121257. The reversal of 11131121220 is 2212113111.

It is a super-2 number, since 2×11131121220² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 11131121220.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7454794 + ... + 7456286.

It is an arithmetic number, because the mean of its divisors is an integer number (327607308).

Almost surely, 2^11131121220 is an apocalyptic number.

11131121220 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 11131121220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15725150784).

11131121220 is an abundant number, since it is smaller than the sum of its proper divisors (20319180348).

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

11131121220 is a wasteful number, since it uses less digits than its factorization.

11131121220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2549 (or 2547 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 11131121220 its reverse (2212113111), we get a palindrome (13343234331).

The spelling of 11131121220 in words is "eleven billion, one hundred thirty-one million, one hundred twenty-one thousand, two hundred twenty".