31331916 has 144 divisors (see below), whose sum is σ = 100638720. Its totient is φ = 7983360.

The previous prime is 31331897. The next prime is 31331921. The reversal of 31331916 is 61913313.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 31331916.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 246645 + ... + 246771.

It is an arithmetic number, because the mean of its divisors is an integer number (698880).

It is a self-describing number.

Almost surely, 2^31331916 is an apocalyptic number.

31331916 is a gapful number since it is divisible by the number (36) 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 31331916, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50319360).

31331916 is an abundant number, since it is smaller than the sum of its proper divisors (69306804).

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

31331916 is a wasteful number, since it uses less digits than its factorization.

31331916 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244 (or 239 counting only the distinct ones).

The product of its digits is 1458, while the sum is 27.

The square root of 31331916 is about 5597.4919383595. The cubic root of 31331916 is about 315.2552428576.

The spelling of 31331916 in words is "thirty-one million, three hundred thirty-one thousand, nine hundred sixteen".