91684391209 has 4 divisors (see below), whose sum is σ = 92049667920. Its totient is φ = 91319114500.

The previous prime is 91684391189. The next prime is 91684391261. The reversal of 91684391209 is 90219348619.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 91684391209 - 2⁹ = 91684390697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91684391609) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 182637979 + ... + 182638480.

It is an arithmetic number, because the mean of its divisors is an integer number (23012416980).

Almost surely, 2^91684391209 is an apocalyptic number.

It is an amenable number.

91684391209 is a deficient number, since it is larger than the sum of its proper divisors (365276711).

91684391209 is a wasteful number, since it uses less digits than its factorization.

91684391209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 365276710.

The product of its (nonzero) digits is 839808, while the sum is 52.

The spelling of 91684391209 in words is "ninety-one billion, six hundred eighty-four million, three hundred ninety-one thousand, two hundred nine".