18221431680 has 768 divisors, whose sum is σ = 71630438400. Its totient is φ = 4368494592.

The previous prime is 18221431673. The next prime is 18221431717. The reversal of 18221431680 is 8613412281.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 143475777 + ... + 143475903.

It is an arithmetic number, because the mean of its divisors is an integer number (93268800).

Almost surely, 2^18221431680 is an apocalyptic number.

18221431680 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 18221431680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35815219200).

18221431680 is an abundant number, since it is smaller than the sum of its proper divisors (53409006720).

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

18221431680 is a wasteful number, since it uses less digits than its factorization.

18221431680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216 (or 179 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The spelling of 18221431680 in words is "eighteen billion, two hundred twenty-one million, four hundred thirty-one thousand, six hundred eighty".