18391920091 has 8 divisors (see below), whose sum is σ = 18528332000. Its totient is φ = 18255948480.

The previous prime is 18391920073. The next prime is 18391920109. The reversal of 18391920091 is 19002919381.

It is an interprime number because it is at equal distance from previous prime (18391920073) and next prime (18391920109).

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 18391920091 - 2¹¹ = 18391918043 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18391920191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25986 + ... + 193543.

It is an arithmetic number, because the mean of its divisors is an integer number (2316041500).

Almost surely, 2^18391920091 is an apocalyptic number.

18391920091 is a deficient number, since it is larger than the sum of its proper divisors (136411909).

18391920091 is a wasteful number, since it uses less digits than its factorization.

18391920091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220149.

The product of its (nonzero) digits is 34992, while the sum is 43.

The spelling of 18391920091 in words is "eighteen billion, three hundred ninety-one million, nine hundred twenty thousand, ninety-one".