31221131112 has 96 divisors (see below), whose sum is σ = 87542208000. Its totient is φ = 10040231040.

The previous prime is 31221131087. The next prime is 31221131119. The reversal of 31221131112 is 21113112213.

31221131112 is a `hidden beast` number, since 312 + 211 + 31 + 112 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

It is not an unprimeable number, because it can be changed into a prime (31221131119) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2999437 + ... + 3009827.

It is an arithmetic number, because the mean of its divisors is an integer number (911898000).

Almost surely, 2^31221131112 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 31221131112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43771104000).

31221131112 is an abundant number, since it is smaller than the sum of its proper divisors (56321076888).

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

31221131112 is a wasteful number, since it uses less digits than its factorization.

31221131112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11871 (or 11864 counting only the distinct ones).

The product of its digits is 72, while the sum is 18.

Adding to 31221131112 its reverse (21113112213), we get a palindrome (52334243325).

The spelling of 31221131112 in words is "thirty-one billion, two hundred twenty-one million, one hundred thirty-one thousand, one hundred twelve".