31138888 has 32 divisors (see below), whose sum is σ = 63918720. Its totient is φ = 14104000.

The previous prime is 31138879. The next prime is 31138889. The reversal of 31138888 is 88883113.

It is a self number, because there is not a number n which added to its sum of digits gives 31138888.

It is not an unprimeable number, because it can be changed into a prime (31138889) 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, 37518 + ... + 38338.

It is an arithmetic number, because the mean of its divisors is an integer number (1997460).

Almost surely, 2^31138888 is an apocalyptic number.

It is an amenable number.

31138888 is an abundant number, since it is smaller than the sum of its proper divisors (32779832).

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

31138888 is a wasteful number, since it uses less digits than its factorization.

31138888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1269 (or 1265 counting only the distinct ones).

The product of its digits is 36864, while the sum is 40.

The square root of 31138888 is about 5580.2229346147. Note that the first 3 decimals coincide. The cubic root of 31138888 is about 314.6065062220.

The spelling of 31138888 in words is "thirty-one million, one hundred thirty-eight thousand, eight hundred eighty-eight".