201221022221100 has 648 divisors, whose sum is σ = 772543089077760. Its totient is φ = 43559265335040.

The previous prime is 201221022221077. The next prime is 201221022221143. The reversal of 201221022221100 is 1122220122102.

It is a happy number.

201221022221100 is a `hidden beast` number, since 20 + 1 + 2 + 210 + 222 + 211 + 0 + 0 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 215 ways as a sum of consecutive naturals, for example, 2854690057 + ... + 2854760543.

It is an arithmetic number, because the mean of its divisors is an integer number (1192196125120).

Almost surely, 2^{201221022221100} is an apocalyptic number.

201221022221100 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 201221022221100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (386271544538880).

201221022221100 is an abundant number, since it is smaller than the sum of its proper divisors (571322066856660).

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

201221022221100 is a wasteful number, since it uses less digits than its factorization.

201221022221100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73947 (or 73930 counting only the distinct ones).

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

Adding to 201221022221100 its reverse (1122220122102), we get a palindrome (202343242343202).

The spelling of 201221022221100 in words is "two hundred one trillion, two hundred twenty-one billion, twenty-two million, two hundred twenty-one thousand, one hundred".