31012021012 has 72 divisors (see below), whose sum is σ = 64038159360. Its totient is φ = 13100592960.

The previous prime is 31012021009. The next prime is 31012021021. The reversal of 31012021012 is 21012021013.

It is a junction number, because it is equal to n+sod(n) for n = 31012020983 and 31012021001.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11967837 + ... + 11970427.

It is an arithmetic number, because the mean of its divisors is an integer number (889418880).

Almost surely, 2^31012021012 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 31012021012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32019079680).

31012021012 is an abundant number, since it is smaller than the sum of its proper divisors (33026138348).

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

31012021012 is a wasteful number, since it uses less digits than its factorization.

31012021012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3461 (or 3452 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 31012021012 its reverse (21012021013), we get a palindrome (52024042025).

Subtracting from 31012021012 its reverse (21012021013), we obtain a palindrome (9999999999).

The spelling of 31012021012 in words is "thirty-one billion, twelve million, twenty-one thousand, twelve".