20121221201 has 4 divisors (see below), whose sum is σ = 20237529012. Its totient is φ = 20004913392.

The previous prime is 20121221161. The next prime is 20121221249. The reversal of 20121221201 is 10212212102.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8570130625 + 11551090576 = 92575^2 + 107476^2 .

It is a cyclic number.

It is not a de Polignac number, because 20121221201 - 2⁶ = 20121221137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20121223201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58153646 + ... + 58153991.

It is an arithmetic number, because the mean of its divisors is an integer number (5059382253).

Almost surely, 2^20121221201 is an apocalyptic number.

It is an amenable number.

20121221201 is a deficient number, since it is larger than the sum of its proper divisors (116307811).

20121221201 is a wasteful number, since it uses less digits than its factorization.

20121221201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116307810.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 20121221201 its reverse (10212212102), we get a palindrome (30333433303).

Subtracting from 20121221201 its reverse (10212212102), we obtain a palindrome (9909009099).

The spelling of 20121221201 in words is "twenty billion, one hundred twenty-one million, two hundred twenty-one thousand, two hundred one".