201221121001 has 8 divisors (see below), whose sum is σ = 201362650760. Its totient is φ = 201079646208.

The previous prime is 201221120999. The next prime is 201221121007. The reversal of 201221121001 is 100121122102.

It can be written as a sum of positive squares in 4 ways, for example, as 2251597401 + 198969523600 = 47451^2 + 446060^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 201221121001 - 2¹ = 201221120999 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (201221121007) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 9446575 + ... + 9467851.

It is an arithmetic number, because the mean of its divisors is an integer number (25170331345).

Almost surely, 2^201221121001 is an apocalyptic number.

It is an amenable number.

201221121001 is a deficient number, since it is larger than the sum of its proper divisors (141529759).

201221121001 is a wasteful number, since it uses less digits than its factorization.

201221121001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27483.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 201221121001 its reverse (100121122102), we get a palindrome (301342243103).

The spelling of 201221121001 in words is "two hundred one billion, two hundred twenty-one million, one hundred twenty-one thousand, one".