31985890 has 16 divisors (see below), whose sum is σ = 57876408. Its totient is φ = 12727296.

The previous prime is 31985881. The next prime is 31985903. The reversal of 31985890 is 9858913.

It can be written as a sum of positive squares in 4 ways, for example, as 24472809 + 7513081 = 4947^2 + 2741^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6357 + ... + 10216.

Almost surely, 2^31985890 is an apocalyptic number.

31985890 is a deficient number, since it is larger than the sum of its proper divisors (25890518).

31985890 is a wasteful number, since it uses less digits than its factorization.

31985890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16773.

The product of its (nonzero) digits is 77760, while the sum is 43.

The square root of 31985890 is about 5655.6069523969. The cubic root of 31985890 is about 317.4335405567.

The spelling of 31985890 in words is "thirty-one million, nine hundred eighty-five thousand, eight hundred ninety".