18945881856 has 378 divisors, whose sum is σ = 62398189560. Its totient is φ = 5734333440.

The previous prime is 18945881821. The next prime is 18945881861. The reversal of 18945881856 is 65818854981.

It is a junction number, because it is equal to n+sod(n) for n = 18945881793 and 18945881802.

It is a congruent number.

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 41 ways as a sum of consecutive naturals, for example, 22581085 + ... + 22581923.

Almost surely, 2^18945881856 is an apocalyptic number.

18945881856 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 18945881856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31199094780).

18945881856 is an abundant number, since it is smaller than the sum of its proper divisors (43452307704).

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

18945881856 is an frugal number, since it uses more digits than its factorization.

18945881856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 895 (or 855 counting only the distinct ones).

The product of its digits is 22118400, while the sum is 63.

The spelling of 18945881856 in words is "eighteen billion, nine hundred forty-five million, eight hundred eighty-one thousand, eight hundred fifty-six".