201221012021100 has 288 divisors, whose sum is σ = 607809097728000. Its totient is φ = 51346705075200.

The previous prime is 201221012021059. The next prime is 201221012021101. The reversal of 201221012021100 is 1120210122102.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 201221012021100.

It is not an unprimeable number, because it can be changed into a prime (201221012021101) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 9316208101 + ... + 9316229699.

It is an arithmetic number, because the mean of its divisors is an integer number (2110448256000).

Almost surely, 2^{201221012021100} is an apocalyptic number.

201221012021100 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 201221012021100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (303904548864000).

201221012021100 is an abundant number, since it is smaller than the sum of its proper divisors (406588085706900).

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

201221012021100 is a wasteful number, since it uses less digits than its factorization.

201221012021100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35473 (or 35466 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 201221012021100 its reverse (1120210122102), we get a palindrome (202341222143202).

The spelling of 201221012021100 in words is "two hundred one trillion, two hundred twenty-one billion, twelve million, twenty-one thousand, one hundred".