21505502200 has 144 divisors (see below), whose sum is σ = 62638100280. Its totient is φ = 6806096640.

The previous prime is 21505502191. The next prime is 21505502243. The reversal of 21505502200 is 220550512.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 42999 + ... + 211801.

Almost surely, 2^21505502200 is an apocalyptic number.

21505502200 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 21505502200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31319050140).

21505502200 is an abundant number, since it is smaller than the sum of its proper divisors (41132598080).

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

21505502200 is a wasteful number, since it uses less digits than its factorization.

21505502200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168846 (or 168830 counting only the distinct ones).

The product of its (nonzero) digits is 1000, while the sum is 22.

The spelling of 21505502200 in words is "twenty-one billion, five hundred five million, five hundred two thousand, two hundred".