31995985 has 16 divisors (see below), whose sum is σ = 43984512. Its totient is φ = 21888000.

The previous prime is 31995983. The next prime is 31996021. The reversal of 31995985 is 58959913.

It is a happy number.

It is not a de Polignac number, because 31995985 - 2¹ = 31995983 is a prime.

It is a super-2 number, since 2×31995985² = 2047486112240450, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31995983) 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, 19185 + ... + 20785.

It is an arithmetic number, because the mean of its divisors is an integer number (2749032).

Almost surely, 2^31995985 is an apocalyptic number.

31995985 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

31995985 is a deficient number, since it is larger than the sum of its proper divisors (11988527).

31995985 is a wasteful number, since it uses less digits than its factorization.

31995985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2184.

The product of its digits is 437400, while the sum is 49.

The square root of 31995985 is about 5656.4993591443. The cubic root of 31995985 is about 317.4669318899.

The spelling of 31995985 in words is "thirty-one million, nine hundred ninety-five thousand, nine hundred eighty-five".