20121031312 has 80 divisors (see below), whose sum is σ = 41904192960. Its totient is φ = 9331531776.

The previous prime is 20121031291. The next prime is 20121031379. The reversal of 20121031312 is 21313012102.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2847688 + ... + 2854744.

It is an arithmetic number, because the mean of its divisors is an integer number (523802412).

Almost surely, 2^20121031312 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20121031312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20952096480).

20121031312 is an abundant number, since it is smaller than the sum of its proper divisors (21783161648).

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

20121031312 is a wasteful number, since it uses less digits than its factorization.

20121031312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7280 (or 7274 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 20121031312 its reverse (21313012102), we get a palindrome (41434043414).

The spelling of 20121031312 in words is "twenty billion, one hundred twenty-one million, thirty-one thousand, three hundred twelve".