31121712 has 80 divisors (see below), whose sum is σ = 90872160. Its totient is φ = 10195200.

The previous prime is 31121711. The next prime is 31121719. The reversal of 31121712 is 21712113.

It is a happy number.

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

It is not an unprimeable number, because it can be changed into a prime (31121711) 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, 25762 + ... + 26942.

It is an arithmetic number, because the mean of its divisors is an integer number (1135902).

Almost surely, 2^31121712 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 31121712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45436080).

31121712 is an abundant number, since it is smaller than the sum of its proper divisors (59750448).

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

31121712 is a wasteful number, since it uses less digits than its factorization.

31121712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1259 (or 1247 counting only the distinct ones).

The product of its digits is 84, while the sum is 18.

The square root of 31121712 is about 5578.6837157165. The cubic root of 31121712 is about 314.5486506428.

Adding to 31121712 its reverse (21712113), we get a palindrome (52833825).

The spelling of 31121712 in words is "thirty-one million, one hundred twenty-one thousand, seven hundred twelve".