31878385208 has 8 divisors (see below), whose sum is σ = 59771972280. Its totient is φ = 15939192600.

The previous prime is 31878385199. The next prime is 31878385213. The reversal of 31878385208 is 80258387813.

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 31878385208.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 1992399068 + ... + 1992399083.

It is an arithmetic number, because the mean of its divisors is an integer number (7471496535).

Almost surely, 2^31878385208 is an apocalyptic number.

It is an amenable number.

31878385208 is a deficient number, since it is larger than the sum of its proper divisors (27893587072).

31878385208 is a wasteful number, since it uses less digits than its factorization.

31878385208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3984798157 (or 3984798153 counting only the distinct ones).

The product of its (nonzero) digits is 2580480, while the sum is 53.

The spelling of 31878385208 in words is "thirty-one billion, eight hundred seventy-eight million, three hundred eighty-five thousand, two hundred eight".