31121312000 has 144 divisors (see below), whose sum is σ = 77825455344. Its totient is φ = 12400640000.

The previous prime is 31121311993. The next prime is 31121312003. The reversal of 31121312000 is 21312113.

It can be written as a sum of positive squares in 8 ways, for example, as 12244750336 + 18876561664 = 110656^2 + 137392^2 .

It is not an unprimeable number, because it can be changed into a prime (31121312003) 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 15 ways as a sum of consecutive naturals, for example, 8990270 + ... + 8993730.

It is an arithmetic number, because the mean of its divisors is an integer number (540454551).

Almost surely, 2^31121312000 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 31121312000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38912727672).

31121312000 is an abundant number, since it is smaller than the sum of its proper divisors (46704143344).

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

31121312000 is an equidigital number, since it uses as much as digits as its factorization.

31121312000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3773 (or 3749 counting only the distinct ones).

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

Adding to 31121312000 its reverse (21312113), we get a palindrome (31142624113).

The spelling of 31121312000 in words is "thirty-one billion, one hundred twenty-one million, three hundred twelve thousand".