31109312 has 56 divisors (see below), whose sum is σ = 67208400. Its totient is φ = 14201856.

The previous prime is 31109297. The next prime is 31109321. The reversal of 31109312 is 21390113.

It is a super-2 number, since 2×31109312² = 1935578586226688, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 115514 + ... + 115782.

It is an arithmetic number, because the mean of its divisors is an integer number (1200150).

Almost surely, 2^31109312 is an apocalyptic number.

31109312 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 31109312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33604200).

31109312 is an abundant number, since it is smaller than the sum of its proper divisors (36099088).

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

31109312 is a wasteful number, since it uses less digits than its factorization.

31109312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 433 (or 423 counting only the distinct ones).

The product of its (nonzero) digits is 162, while the sum is 20.

The square root of 31109312 is about 5577.5722317152. The cubic root of 31109312 is about 314.5068692930.

Adding to 31109312 its reverse (21390113), we get a palindrome (52499425).

The spelling of 31109312 in words is "thirty-one million, one hundred nine thousand, three hundred twelve".