11311131220 has 24 divisors (see below), whose sum is σ = 25150633704. Its totient is φ = 4258308096.

The previous prime is 11311131217. The next prime is 11311131229. The reversal of 11311131220 is 2213111311.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 109872324 + 11201258896 = 10482^2 + 105836^2 .

It is a junction number, because it is equal to n+sod(n) for n = 11311131194 and 11311131203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11311131229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16633677 + ... + 16634356.

It is an arithmetic number, because the mean of its divisors is an integer number (1047943071).

Almost surely, 2^11311131220 is an apocalyptic number.

11311131220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

11311131220 is an abundant number, since it is smaller than the sum of its proper divisors (13839502484).

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

11311131220 is a wasteful number, since it uses less digits than its factorization.

11311131220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33268059 (or 33268057 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 16.

Adding to 11311131220 its reverse (2213111311), we get a palindrome (13524242531).

The spelling of 11311131220 in words is "eleven billion, three hundred eleven million, one hundred thirty-one thousand, two hundred twenty".