18006563456 has 64 divisors (see below), whose sum is σ = 41223960960. Its totient is φ = 7674393600.

The previous prime is 18006563441. The next prime is 18006563461. The reversal of 18006563456 is 65436560081.

It is a tau number, because it is divible by the number of its divisors (64).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 106661 + ... + 217691.

It is an arithmetic number, because the mean of its divisors is an integer number (644124390).

Almost surely, 2^18006563456 is an apocalyptic number.

18006563456 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18006563456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20611980480).

18006563456 is an abundant number, since it is smaller than the sum of its proper divisors (23217397504).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18006563456 is a wasteful number, since it uses less digits than its factorization.

18006563456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111233 (or 111221 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 44.

The spelling of 18006563456 in words is "eighteen billion, six million, five hundred sixty-three thousand, four hundred fifty-six".