31131322112 has 144 divisors (see below), whose sum is σ = 71453007360. Its totient is φ = 13398528000.

The previous prime is 31131322111. The next prime is 31131322153. The reversal of 31131322112 is 21122313113.

It is a happy number.

It is a super-2 number, since 2×31131322112² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31131322111) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6539189 + ... + 6543947.

It is an arithmetic number, because the mean of its divisors is an integer number (496201440).

Almost surely, 2^31131322112 is an apocalyptic number.

31131322112 is a gapful number since it is divisible by the number (32) 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 31131322112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35726503680).

31131322112 is an abundant number, since it is smaller than the sum of its proper divisors (40321685248).

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

31131322112 is a wasteful number, since it uses less digits than its factorization.

31131322112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4910 (or 4896 counting only the distinct ones).

The product of its digits is 216, while the sum is 20.

Adding to 31131322112 its reverse (21122313113), we get a palindrome (52253635225).

The spelling of 31131322112 in words is "thirty-one billion, one hundred thirty-one million, three hundred twenty-two thousand, one hundred twelve".