87931309688 has 8 divisors (see below), whose sum is σ = 164871205680.
Its totient is φ = 43965654840.
The previous prime is 87931309681. The next prime is 87931309699. The reversal of 87931309688 is 88690313978.
It is a tau number, because it is divible by the number of its divisors (8).
It is a self number, because there is not a number n which added to its sum of digits gives 87931309688.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (87931309681) 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, 5495706848 + ... + 5495706863.
It is an arithmetic number, because the mean of its divisors is an integer number (20608900710).
Almost surely, 287931309688 is an apocalyptic number.
It is an amenable number.
87931309688 is a deficient number, since it is larger than the sum of its proper divisors (76939895992).
87931309688 is a wasteful number, since it uses less digits than its factorization.
87931309688 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 10991413717 (or 10991413713 counting only the distinct ones).
The product of its (nonzero) digits is 15676416, while the sum is 62.
The spelling of 87931309688 in words is "eighty-seven billion, nine hundred thirty-one million, three hundred nine thousand, six hundred eighty-eight".