221221305200 has 60 divisors (see below), whose sum is σ = 607410505680. Its totient is φ = 75847303680.

The previous prime is 221221305199. The next prime is 221221305233. The reversal of 221221305200 is 2503122122.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 39501005 + ... + 39506604.

It is an arithmetic number, because the mean of its divisors is an integer number (10123508428).

Almost surely, 2^221221305200 is an apocalyptic number.

221221305200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221221305200 is an abundant number, since it is smaller than the sum of its proper divisors (386189200480).

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

221221305200 is a wasteful number, since it uses less digits than its factorization.

221221305200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79007634 (or 79007623 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

Adding to 221221305200 its reverse (2503122122), we get a palindrome (223724427322).

The spelling of 221221305200 in words is "two hundred twenty-one billion, two hundred twenty-one million, three hundred five thousand, two hundred".