31311002120 has 128 divisors (see below), whose sum is σ = 76191667200. Its totient is φ = 11542051584.

The previous prime is 31311002113. The next prime is 31311002123. The reversal of 31311002120 is 2120011313.

It is a junction number, because it is equal to n+sod(n) for n = 31311002095 and 31311002104.

It is not an unprimeable number, because it can be changed into a prime (31311002123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8593019 + ... + 8596661.

It is an arithmetic number, because the mean of its divisors is an integer number (595247400).

Almost surely, 2^31311002120 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 31311002120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38095833600).

31311002120 is an abundant number, since it is smaller than the sum of its proper divisors (44880665080).

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

31311002120 is a wasteful number, since it uses less digits than its factorization.

31311002120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3979 (or 3975 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 14.

Adding to 31311002120 its reverse (2120011313), we get a palindrome (33431013433).

The spelling of 31311002120 in words is "thirty-one billion, three hundred eleven million, two thousand, one hundred twenty".