11512031220 has 144 divisors (see below), whose sum is σ = 36896321280. Its totient is φ = 2897337600.

The previous prime is 11512031213. The next prime is 11512031221. The reversal of 11512031220 is 2213021511.

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 = 11512031193 and 11512031202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11512031221) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 920610 + ... + 933030.

Almost surely, 2^11512031220 is an apocalyptic number.

11512031220 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 11512031220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18448160640).

11512031220 is an abundant number, since it is smaller than the sum of its proper divisors (25384290060).

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

11512031220 is a wasteful number, since it uses less digits than its factorization.

11512031220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12726 (or 12721 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

Adding to 11512031220 its reverse (2213021511), we get a palindrome (13725052731).

The spelling of 11512031220 in words is "eleven billion, five hundred twelve million, thirty-one thousand, two hundred twenty".