18421860646 has 48 divisors (see below), whose sum is σ = 33139602720. Its totient is φ = 7514640000.

The previous prime is 18421860641. The next prime is 18421860673. The reversal of 18421860646 is 64606812481.

It is a Smith number, since the sum of its digits (46) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 18421860596 and 18421860605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18421860641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2042146 + ... + 2051146.

It is an arithmetic number, because the mean of its divisors is an integer number (690408390).

Almost surely, 2^18421860646 is an apocalyptic number.

18421860646 is a deficient number, since it is larger than the sum of its proper divisors (14717742074).

18421860646 is an equidigital number, since it uses as much as digits as its factorization.

18421860646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9181 (or 9110 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 46.

The spelling of 18421860646 in words is "eighteen billion, four hundred twenty-one million, eight hundred sixty thousand, six hundred forty-six".