31728366 has 48 divisors (see below), whose sum is σ = 73092240. Its totient is φ = 9918720.

The previous prime is 31728353. The next prime is 31728421. The reversal of 31728366 is 66382713.

It is a happy number.

31728366 is a `hidden beast` number, since 317 + 283 + 66 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 31728366.

It is a congruent number.

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 23 ways as a sum of consecutive naturals, for example, 38236 + ... + 39056.

It is an arithmetic number, because the mean of its divisors is an integer number (1522755).

Almost surely, 2^31728366 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31728366, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36546120).

31728366 is an abundant number, since it is smaller than the sum of its proper divisors (41363874).

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

31728366 is a wasteful number, since it uses less digits than its factorization.

31728366 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 961 (or 958 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 31728366 is about 5632.7938005931. The cubic root of 31728366 is about 316.5793396628.

The spelling of 31728366 in words is "thirty-one million, seven hundred twenty-eight thousand, three hundred sixty-six".