91821716633 has 4 divisors (see below), whose sum is σ = 97222994100. Its totient is φ = 86420439168.

The previous prime is 91821716617. The next prime is 91821716641. The reversal of 91821716633 is 33661712819.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 78507556864 + 13314159769 = 280192^2 + 115387^2 .

It is a cyclic number.

It is not a de Polignac number, because 91821716633 - 2⁴ = 91821716617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91821716603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2700638708 + ... + 2700638741.

It is an arithmetic number, because the mean of its divisors is an integer number (24305748525).

Almost surely, 2^91821716633 is an apocalyptic number.

It is an amenable number.

91821716633 is a deficient number, since it is larger than the sum of its proper divisors (5401277467).

91821716633 is a wasteful number, since it uses less digits than its factorization.

91821716633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5401277466.

The product of its digits is 326592, while the sum is 47.

The spelling of 91821716633 in words is "ninety-one billion, eight hundred twenty-one million, seven hundred sixteen thousand, six hundred thirty-three".