21550387200 has 624 divisors, whose sum is σ = 76785710400. Its totient is φ = 5321523200.

The previous prime is 21550387193. The next prime is 21550387213. The reversal of 21550387200 is 278305512.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 365260771 + ... + 365260829.

Almost surely, 2^21550387200 is an apocalyptic number.

21550387200 is a gapful number since it is divisible by the number (20) 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 21550387200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38392855200).

21550387200 is an abundant number, since it is smaller than the sum of its proper divisors (55235323200).

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

21550387200 is a wasteful number, since it uses less digits than its factorization.

21550387200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166 (or 139 counting only the distinct ones).

The product of its (nonzero) digits is 16800, while the sum is 33.

The spelling of 21550387200 in words is "twenty-one billion, five hundred fifty million, three hundred eighty-seven thousand, two hundred".