31871138 has 16 divisors (see below), whose sum is σ = 51714936. Its totient is φ = 14643840.

The previous prime is 31871137. The next prime is 31871183. The reversal of 31871138 is 83117813.

It can be written as a sum of positive squares in 4 ways, for example, as 21132409 + 10738729 = 4597^2 + 3277^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (31871137) 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 7 ways as a sum of consecutive naturals, for example, 3428 + ... + 8688.

Almost surely, 2^31871138 is an apocalyptic number.

31871138 is a deficient number, since it is larger than the sum of its proper divisors (19843798).

31871138 is a wasteful number, since it uses less digits than its factorization.

31871138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5509.

The product of its digits is 4032, while the sum is 32.

The square root of 31871138 is about 5645.4528604887. The cubic root of 31871138 is about 317.0534794188.

The spelling of 31871138 in words is "thirty-one million, eight hundred seventy-one thousand, one hundred thirty-eight".