91665191912321 has 8 divisors (see below), whose sum is σ = 99602245881600. Its totient is φ = 84039394961520.

The previous prime is 91665191912209. The next prime is 91665191912351. The reversal of 91665191912321 is 12321919156619.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 91665191912321 - 2¹⁰ = 91665191911297 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91665191912351) 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, 77814254006 + ... + 77814255183.

It is an arithmetic number, because the mean of its divisors is an integer number (12450280735200).

Almost surely, 2^{91665191912321} is an apocalyptic number.

It is an amenable number.

91665191912321 is a deficient number, since it is larger than the sum of its proper divisors (7937053969279).

91665191912321 is a wasteful number, since it uses less digits than its factorization.

91665191912321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155628509239.

The product of its digits is 1574640, while the sum is 56.

The spelling of 91665191912321 in words is "ninety-one trillion, six hundred sixty-five billion, one hundred ninety-one million, nine hundred twelve thousand, three hundred twenty-one".