18805218547 has 4 divisors (see below), whose sum is σ = 19263882456. Its totient is φ = 18346554640.

The previous prime is 18805218541. The next prime is 18805218571. The reversal of 18805218547 is 74581250881.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18805218547 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18805218547.

It is not an unprimeable number, because it can be changed into a prime (18805218541) 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 3 ways as a sum of consecutive naturals, for example, 229331893 + ... + 229331974.

It is an arithmetic number, because the mean of its divisors is an integer number (4815970614).

Almost surely, 2^18805218547 is an apocalyptic number.

18805218547 is a deficient number, since it is larger than the sum of its proper divisors (458663909).

18805218547 is an equidigital number, since it uses as much as digits as its factorization.

18805218547 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 458663908.

The product of its (nonzero) digits is 716800, while the sum is 49.

The spelling of 18805218547 in words is "eighteen billion, eight hundred five million, two hundred eighteen thousand, five hundred forty-seven".