21221121022200 has 576 divisors, whose sum is σ = 82484108179200. Its totient is φ = 4832231116800.

The previous prime is 21221121022193. The next prime is 21221121022219. The reversal of 21221121022200 is 222012112212.

It is a happy number.

21221121022200 is a `hidden beast` number, since 21 + 2 + 211 + 210 + 2 + 220 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 169247131 + ... + 169372469.

It is an arithmetic number, because the mean of its divisors is an integer number (143201576700).

Almost surely, 2^{21221121022200} is an apocalyptic number.

21221121022200 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 21221121022200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41242054089600).

21221121022200 is an abundant number, since it is smaller than the sum of its proper divisors (61262987157000).

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

21221121022200 is a wasteful number, since it uses less digits than its factorization.

21221121022200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125892 (or 125880 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21221121022200 its reverse (222012112212), we get a palindrome (21443133134412).

The spelling of 21221121022200 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred twenty-one million, twenty-two thousand, two hundred".