91663992668 has 24 divisors (see below), whose sum is σ = 160734109200. Its totient is φ = 45740044800.

The previous prime is 91663992661. The next prime is 91663992671. The reversal of 91663992668 is 86629936619.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91663992661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4972268 + ... + 4990668.

It is an arithmetic number, because the mean of its divisors is an integer number (6697254550).

Almost surely, 2^91663992668 is an apocalyptic number.

It is an amenable number.

91663992668 is a deficient number, since it is larger than the sum of its proper divisors (69070116532).

91663992668 is a wasteful number, since it uses less digits than its factorization.

91663992668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20837 (or 20835 counting only the distinct ones).

The product of its digits is 45349632, while the sum is 65.

The spelling of 91663992668 in words is "ninety-one billion, six hundred sixty-three million, nine hundred ninety-two thousand, six hundred sixty-eight".