18521766656 has 144 divisors (see below), whose sum is σ = 40418955360. Its totient is φ = 8440381440.

The previous prime is 18521766629. The next prime is 18521766689. The reversal of 18521766656 is 65666712581.

It is a happy number.

It is a zygodrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 18521766598 and 18521766607.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17456366 + ... + 17457426.

It is an arithmetic number, because the mean of its divisors is an integer number (280687190).

Almost surely, 2^18521766656 is an apocalyptic number.

18521766656 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 18521766656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20209477680).

18521766656 is an abundant number, since it is smaller than the sum of its proper divisors (21897188704).

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

18521766656 is a wasteful number, since it uses less digits than its factorization.

18521766656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1230 (or 1216 counting only the distinct ones).

The product of its digits is 3628800, while the sum is 53.

The spelling of 18521766656 in words is "eighteen billion, five hundred twenty-one million, seven hundred sixty-six thousand, six hundred fifty-six".