91661638296960 has 1280 divisors, whose sum is σ = 340505432467200. Its totient is φ = 23481300418560.

The previous prime is 91661638296889. The next prime is 91661638296989. The reversal of 91661638296960 is 6969283616619.

91661638296960 is a `hidden beast` number, since 9 + 1 + 66 + 16 + 382 + 96 + 96 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 40079420937 + ... + 40079423223.

It is an arithmetic number, because the mean of its divisors is an integer number (266019869115).

Almost surely, 2^{91661638296960} is an apocalyptic number.

91661638296960 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91661638296960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (170252716233600).

91661638296960 is an abundant number, since it is smaller than the sum of its proper divisors (248843794170240).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91661638296960 is a wasteful number, since it uses less digits than its factorization.

91661638296960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2641 (or 2620 counting only the distinct ones).

The product of its (nonzero) digits is 272097792, while the sum is 72.

The spelling of 91661638296960 in words is "ninety-one trillion, six hundred sixty-one billion, six hundred thirty-eight million, two hundred ninety-six thousand, nine hundred sixty".