11231131220 has 24 divisors (see below), whose sum is σ = 23757537384. Its totient is φ = 4459659776.

The previous prime is 11231131207. The next prime is 11231131231. The reversal of 11231131220 is 2213113211.

It can be written as a sum of positive squares in 4 ways, for example, as 8271376 + 11222859844 = 2876^2 + 105938^2 .

It is a super-2 number, since 2×11231131220² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 2046737 + ... + 2052216.

It is an arithmetic number, because the mean of its divisors is an integer number (989897391).

Almost surely, 2^11231131220 is an apocalyptic number.

11231131220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

11231131220 is an abundant number, since it is smaller than the sum of its proper divisors (12526406164).

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

11231131220 is a wasteful number, since it uses less digits than its factorization.

11231131220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4099099 (or 4099097 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 11231131220 its reverse (2213113211), we get a palindrome (13444244431).

The spelling of 11231131220 in words is "eleven billion, two hundred thirty-one million, one hundred thirty-one thousand, two hundred twenty".