201221210221000 has 128 divisors (see below), whose sum is σ = 474151007547360. Its totient is φ = 79927406592000.

The previous prime is 201221210220997. The next prime is 201221210221037. The reversal of 201221210221000 is 122012122102.

It is a happy number.

It can be written as a sum of positive squares in 16 ways, for example, as 5741496484164 + 195479713736836 = 2396142^2 + 13981406^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 83890362 + ... + 86255638.

Almost surely, 2^{201221210221000} is an apocalyptic number.

201221210221000 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 201221210221000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (237075503773680).

201221210221000 is an abundant number, since it is smaller than the sum of its proper divisors (272929797326360).

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

201221210221000 is a wasteful number, since it uses less digits than its factorization.

201221210221000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2365892 (or 2365878 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 201221210221000 its reverse (122012122102), we get a palindrome (201343222343102).

The spelling of 201221210221000 in words is "two hundred one trillion, two hundred twenty-one billion, two hundred ten million, two hundred twenty-one thousand".