18381218547 has 16 divisors (see below), whose sum is σ = 24639577088. Its totient is φ = 12188599200.

The previous prime is 18381218539. The next prime is 18381218549. The reversal of 18381218547 is 74581218381.

It is not a de Polignac number, because 18381218547 - 2³ = 18381218539 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18381218496 and 18381218505.

It is not an unprimeable number, because it can be changed into a prime (18381218549) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 800172 + ... + 822822.

It is an arithmetic number, because the mean of its divisors is an integer number (1539973568).

Almost surely, 2^18381218547 is an apocalyptic number.

18381218547 is a deficient number, since it is larger than the sum of its proper divisors (6258358541).

18381218547 is a wasteful number, since it uses less digits than its factorization.

18381218547 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24090.

The product of its digits is 430080, while the sum is 48.

The spelling of 18381218547 in words is "eighteen billion, three hundred eighty-one million, two hundred eighteen thousand, five hundred forty-seven".