11231231220 has 144 divisors (see below), whose sum is σ = 39351469248. Its totient is φ = 2562554880.

The previous prime is 11231231213. The next prime is 11231231243. The reversal of 11231231220 is 2213213211.

It is a super-2 number, since 2×11231231220² (a number of 21 digits) contains 22 as substring.

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 = 11231231193 and 11231231202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 133174 + ... + 200493.

It is an arithmetic number, because the mean of its divisors is an integer number (273274092).

Almost surely, 2^11231231220 is an apocalyptic number.

11231231220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

11231231220 is an abundant number, since it is smaller than the sum of its proper divisors (28120238028).

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

11231231220 is a wasteful number, since it uses less digits than its factorization.

11231231220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333710 (or 333705 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 11231231220 its reverse (2213213211), we get a palindrome (13444444431).

The spelling of 11231231220 in words is "eleven billion, two hundred thirty-one million, two hundred thirty-one thousand, two hundred twenty".