18221515200 has 504 divisors, whose sum is σ = 75837958560. Its totient is φ = 4062412800.

The previous prime is 18221515187. The next prime is 18221515217. The reversal of 18221515200 is 251512281.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (504).

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 71 ways as a sum of consecutive naturals, for example, 4130596 + ... + 4135004.

It is an arithmetic number, because the mean of its divisors is an integer number (150472140).

Almost surely, 2^18221515200 is an apocalyptic number.

18221515200 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 18221515200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37918979280).

18221515200 is an abundant number, since it is smaller than the sum of its proper divisors (57616443360).

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

18221515200 is a wasteful number, since it uses less digits than its factorization.

18221515200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4485 (or 4467 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 27.

The spelling of 18221515200 in words is "eighteen billion, two hundred twenty-one million, five hundred fifteen thousand, two hundred".