31971985 has 32 divisors (see below), whose sum is σ = 42550272. Its totient is φ = 22963200.

The previous prime is 31971977. The next prime is 31972009. The reversal of 31971985 is 58917913.

It is not a de Polignac number, because 31971985 - 2³ = 31971977 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 211660 + ... + 211810.

It is an arithmetic number, because the mean of its divisors is an integer number (1329696).

Almost surely, 2^31971985 is an apocalyptic number.

It is an amenable number.

31971985 is a deficient number, since it is larger than the sum of its proper divisors (10578287).

31971985 is a wasteful number, since it uses less digits than its factorization.

31971985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 273.

The product of its digits is 68040, while the sum is 43.

The square root of 31971985 is about 5654.3775077368. The cubic root of 31971985 is about 317.3875353427.

The spelling of 31971985 in words is "thirty-one million, nine hundred seventy-one thousand, nine hundred eighty-five".