18643806720 has 1280 divisors, whose sum is σ = 85983068160. Its totient is φ = 3715891200.

The previous prime is 18643806719. The next prime is 18643806757. The reversal of 18643806720 is 2760834681.

It is a tau number, because it is divible by the number of its divisors (1280).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

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 127 ways as a sum of consecutive naturals, for example, 164989384 + ... + 164989496.

It is an arithmetic number, because the mean of its divisors is an integer number (67174272).

Almost surely, 2^18643806720 is an apocalyptic number.

18643806720 is a gapful number since it is divisible by the number (10) 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 18643806720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42991534080).

18643806720 is an abundant number, since it is smaller than the sum of its proper divisors (67339261440).

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

18643806720 is a wasteful number, since it uses less digits than its factorization.

18643806720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194 (or 172 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 45.

The spelling of 18643806720 in words is "eighteen billion, six hundred forty-three million, eight hundred six thousand, seven hundred twenty".