20121131112 has 16 divisors (see below), whose sum is σ = 50302827840. Its totient is φ = 6707043696.

The previous prime is 20121131111. The next prime is 20121131113. The reversal of 20121131112 is 21113112102.

It is an interprime number because it is at equal distance from previous prime (20121131111) and next prime (20121131113).

It is a junction number, because it is equal to n+sod(n) for n = 20121131091 and 20121131100.

It is not an unprimeable number, because it can be changed into a prime (20121131111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 419190208 + ... + 419190255.

It is an arithmetic number, because the mean of its divisors is an integer number (3143926740).

Almost surely, 2^20121131112 is an apocalyptic number.

It is an amenable number.

20121131112 is an abundant number, since it is smaller than the sum of its proper divisors (30181696728).

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

20121131112 is a wasteful number, since it uses less digits than its factorization.

20121131112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 838380472 (or 838380468 counting only the distinct ones).

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

Adding to 20121131112 its reverse (21113112102), we get a palindrome (41234243214).

The spelling of 20121131112 in words is "twenty billion, one hundred twenty-one million, one hundred thirty-one thousand, one hundred twelve".