201221221000 has 64 divisors (see below), whose sum is σ = 473297788080. Its totient is φ = 80071372800.

The previous prime is 201221220979. The next prime is 201221221009. The reversal of 201221221000 is 122122102.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 7468070724 + 193753150276 = 86418^2 + 440174^2 .

It is not an unprimeable number, because it can be changed into a prime (201221221009) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 328299 + ... + 714298.

Almost surely, 2^201221221000 is an apocalyptic number.

201221221000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

201221221000 is an abundant number, since it is smaller than the sum of its proper divisors (272076567080).

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

201221221000 is a wasteful number, since it uses less digits than its factorization.

201221221000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1042811 (or 1042797 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 201221221000 its reverse (122122102), we get a palindrome (201343343102).

The spelling of 201221221000 in words is "two hundred one billion, two hundred twenty-one million, two hundred twenty-one thousand".