91785639663 has 6 divisors (see below), whose sum is σ = 132579257304. Its totient is φ = 61190426436.

The previous prime is 91785639661. The next prime is 91785639667. The reversal of 91785639663 is 36693658719.

91785639663 is a `hidden beast` number, since 9 + 1 + 7 + 8 + 563 + 9 + 6 + 63 = 666.

It is not a de Polignac number, because 91785639663 - 2¹ = 91785639661 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 91785639663.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91785639661) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5099202195 + ... + 5099202212.

It is an arithmetic number, because the mean of its divisors is an integer number (22096542884).

Almost surely, 2^91785639663 is an apocalyptic number.

91785639663 is a deficient number, since it is larger than the sum of its proper divisors (40793617641).

91785639663 is a wasteful number, since it uses less digits than its factorization.

91785639663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10198404413 (or 10198404410 counting only the distinct ones).

The product of its digits is 44089920, while the sum is 63.

The spelling of 91785639663 in words is "ninety-one billion, seven hundred eighty-five million, six hundred thirty-nine thousand, six hundred sixty-three".