18642216478 has 4 divisors (see below), whose sum is σ = 27963324720. Its totient is φ = 9321108238.

The previous prime is 18642216469. The next prime is 18642216497. The reversal of 18642216478 is 87461224681.

It is a happy number.

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

It is a super-2 number, since 2×18642216478² (a number of 21 digits) contains 22 as substring.

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, 4660554118 + ... + 4660554121.

It is an arithmetic number, because the mean of its divisors is an integer number (6990831180).

Almost surely, 2^18642216478 is an apocalyptic number.

18642216478 is a deficient number, since it is larger than the sum of its proper divisors (9321108242).

18642216478 is an equidigital number, since it uses as much as digits as its factorization.

18642216478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9321108241.

The product of its digits is 1032192, while the sum is 49.

The spelling of 18642216478 in words is "eighteen billion, six hundred forty-two million, two hundred sixteen thousand, four hundred seventy-eight".