20121131312 has 40 divisors (see below), whose sum is σ = 40271767680. Its totient is φ = 9728893440.

The previous prime is 20121131293. The next prime is 20121131369. The reversal of 20121131312 is 21313112102.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 696614 + ... + 724922.

It is an arithmetic number, because the mean of its divisors is an integer number (1006794192).

Almost surely, 2^20121131312 is an apocalyptic number.

It is an amenable number.

20121131312 is an abundant number, since it is smaller than the sum of its proper divisors (20150636368).

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

20121131312 is a wasteful number, since it uses less digits than its factorization.

20121131312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29781 (or 29775 counting only the distinct ones).

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

Adding to 20121131312 its reverse (21313112102), we get a palindrome (41434243414).

The spelling of 20121131312 in words is "twenty billion, one hundred twenty-one million, one hundred thirty-one thousand, three hundred twelve".