91997912168 has 16 divisors (see below), whose sum is σ = 172691450880. Its totient is φ = 45946858608.

The previous prime is 91997912131. The next prime is 91997912203. The reversal of 91997912168 is 86121979919.

It is a self number, because there is not a number n which added to its sum of digits gives 91997912168.

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 in 3 ways as a sum of consecutive naturals, for example, 6504680 + ... + 6518807.

It is an arithmetic number, because the mean of its divisors is an integer number (10793215680).

Almost surely, 2^91997912168 is an apocalyptic number.

It is an amenable number.

91997912168 is a deficient number, since it is larger than the sum of its proper divisors (80693538712).

91997912168 is a wasteful number, since it uses less digits than its factorization.

91997912168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13024376 (or 13024372 counting only the distinct ones).

The product of its digits is 4408992, while the sum is 62.

The spelling of 91997912168 in words is "ninety-one billion, nine hundred ninety-seven million, nine hundred twelve thousand, one hundred sixty-eight".