18221815180800 has 3600 divisors, whose sum is σ = 85304834725968. Its totient is φ = 3682035302400.

The previous prime is 18221815180729. The next prime is 18221815180817. The reversal of 18221815180800 is 808151812281.

It is a happy number.

18221815180800 is a `hidden beast` number, since 182 + 218 + 1 + 5 + 180 + 80 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (3600).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 359 ways as a sum of consecutive naturals, for example, 161255001544 + ... + 161255001656.

Almost surely, 2^{18221815180800} is an apocalyptic number.

18221815180800 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 18221815180800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42652417362984).

18221815180800 is an abundant number, since it is smaller than the sum of its proper divisors (67083019545168).

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

18221815180800 is a wasteful number, since it uses less digits than its factorization.

18221815180800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239 (or 194 counting only the distinct ones).

The product of its (nonzero) digits is 81920, while the sum is 45.

The spelling of 18221815180800 in words is "eighteen trillion, two hundred twenty-one billion, eight hundred fifteen million, one hundred eighty thousand, eight hundred".