31985240 has 48 divisors (see below), whose sum is σ = 83721600. Its totient is φ = 10965696.

The previous prime is 31985201. The next prime is 31985243. The reversal of 31985240 is 4258913.

It is a junction number, because it is equal to n+sod(n) for n = 31985197 and 31985206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31985243) 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 11 ways as a sum of consecutive naturals, for example, 6200 + ... + 10119.

It is an arithmetic number, because the mean of its divisors is an integer number (1744200).

Almost surely, 2^31985240 is an apocalyptic number.

It is an amenable number.

31985240 is an abundant number, since it is smaller than the sum of its proper divisors (51736360).

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

31985240 is a wasteful number, since it uses less digits than its factorization.

31985240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16344 (or 16333 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 31985240 is about 5655.5494870083. The cubic root of 31985240 is about 317.4313903044.

The spelling of 31985240 in words is "thirty-one million, nine hundred eighty-five thousand, two hundred forty".