31188940 has 12 divisors (see below), whose sum is σ = 65496816. Its totient is φ = 12475568.

The previous prime is 31188929. The next prime is 31188947. The reversal of 31188940 is 4988113.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 31188896 and 31188905.

It is not an unprimeable number, because it can be changed into a prime (31188947) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 779704 + ... + 779743.

It is an arithmetic number, because the mean of its divisors is an integer number (5458068).

Almost surely, 2^31188940 is an apocalyptic number.

It is an amenable number.

31188940 is an abundant number, since it is smaller than the sum of its proper divisors (34307876).

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

31188940 is a wasteful number, since it uses less digits than its factorization.

31188940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1559456 (or 1559454 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 34.

The square root of 31188940 is about 5584.7059009405. The cubic root of 31188940 is about 314.7749799689.

The spelling of 31188940 in words is "thirty-one million, one hundred eighty-eight thousand, nine hundred forty".