31985538 has 32 divisors (see below), whose sum is σ = 70760256. Its totient is φ = 9574848.

The previous prime is 31985537. The next prime is 31985557. The reversal of 31985538 is 83558913.

It is a super-2 number, since 2×31985538² = 2046149282298888, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 31985538.

It is not an unprimeable number, because it can be changed into a prime (31985537) 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 15 ways as a sum of consecutive naturals, for example, 2656 + ... + 8427.

It is an arithmetic number, because the mean of its divisors is an integer number (2211258).

Almost surely, 2^31985538 is an apocalyptic number.

31985538 is an abundant number, since it is smaller than the sum of its proper divisors (38774718).

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

31985538 is a wasteful number, since it uses less digits than its factorization.

31985538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11138.

The product of its digits is 129600, while the sum is 42.

The square root of 31985538 is about 5655.5758327513. The cubic root of 31985538 is about 317.4323761160.

It can be divided in two parts, 31985 and 538, that added together give a palindrome (32523).

The spelling of 31985538 in words is "thirty-one million, nine hundred eighty-five thousand, five hundred thirty-eight".