31891138288 has 10 divisors (see below), whose sum is σ = 61789080464. Its totient is φ = 15945569136.

The previous prime is 31891138277. The next prime is 31891138289. The reversal of 31891138288 is 88283119813.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31891138289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 996598056 + ... + 996598087.

Almost surely, 2^31891138288 is an apocalyptic number.

It is an amenable number.

31891138288 is a deficient number, since it is larger than the sum of its proper divisors (29897942176).

31891138288 is a wasteful number, since it uses less digits than its factorization.

31891138288 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1993196151 (or 1993196145 counting only the distinct ones).

The product of its digits is 663552, while the sum is 52.

The spelling of 31891138288 in words is "thirty-one billion, eight hundred ninety-one million, one hundred thirty-eight thousand, two hundred eighty-eight".