31689768 has 128 divisors (see below), whose sum is σ = 95800320. Its totient is φ = 8616960.

The previous prime is 31689733. The next prime is 31689769. The reversal of 31689768 is 86798613.

It is not an unprimeable number, because it can be changed into a prime (31689769) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 103071 + ... + 103377.

It is an arithmetic number, because the mean of its divisors is an integer number (748440).

Almost surely, 2^31689768 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 31689768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47900160).

31689768 is an abundant number, since it is smaller than the sum of its proper divisors (64110552).

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

31689768 is a wasteful number, since it uses less digits than its factorization.

31689768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 367 (or 363 counting only the distinct ones).

The product of its digits is 435456, while the sum is 48.

The square root of 31689768 is about 5629.3665718267. The cubic root of 31689768 is about 316.4509131763.

The spelling of 31689768 in words is "thirty-one million, six hundred eighty-nine thousand, seven hundred sixty-eight".