18518543894 has 4 divisors (see below), whose sum is σ = 27777815844. Its totient is φ = 9259271946.

The previous prime is 18518543881. The next prime is 18518543929. The reversal of 18518543894 is 49834581581.

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

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 4629635972 + ... + 4629635975.

It is an arithmetic number, because the mean of its divisors is an integer number (6944453961).

Almost surely, 2^18518543894 is an apocalyptic number.

18518543894 is a deficient number, since it is larger than the sum of its proper divisors (9259271950).

18518543894 is an equidigital number, since it uses as much as digits as its factorization.

18518543894 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9259271949.

The product of its digits is 5529600, while the sum is 56.

The spelling of 18518543894 in words is "eighteen billion, five hundred eighteen million, five hundred forty-three thousand, eight hundred ninety-four".