18221471688 has 64 divisors (see below), whose sum is σ = 52838415360. Its totient is φ = 5128428096.

The previous prime is 18221471657. The next prime is 18221471717. The reversal of 18221471688 is 88617412281.

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 798156 + ... + 820667.

It is an arithmetic number, because the mean of its divisors is an integer number (825600240).

Almost surely, 2^18221471688 is an apocalyptic number.

It is an amenable number.

18221471688 is an abundant number, since it is smaller than the sum of its proper divisors (34616943672).

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

18221471688 is a wasteful number, since it uses less digits than its factorization.

18221471688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1618906 (or 1618902 counting only the distinct ones).

The product of its digits is 344064, while the sum is 48.

The spelling of 18221471688 in words is "eighteen billion, two hundred twenty-one million, four hundred seventy-one thousand, six hundred eighty-eight".