18447055891 has 8 divisors (see below), whose sum is σ = 20270953584. Its totient is φ = 16647640320.

The previous prime is 18447055877. The next prime is 18447055937. The reversal of 18447055891 is 19855074481.

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 18447055891 - 2⁹ = 18447055379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18447055871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6118950 + ... + 6121963.

It is an arithmetic number, because the mean of its divisors is an integer number (2533869198).

Almost surely, 2^18447055891 is an apocalyptic number.

18447055891 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

18447055891 is a deficient number, since it is larger than the sum of its proper divisors (1823897693).

18447055891 is a wasteful number, since it uses less digits than its factorization.

18447055891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12241061.

The product of its (nonzero) digits is 1612800, while the sum is 52.

The spelling of 18447055891 in words is "eighteen billion, four hundred forty-seven million, fifty-five thousand, eight hundred ninety-one".