20001201221 has 4 divisors (see below), whose sum is σ = 20105919744. Its totient is φ = 19896482700.

The previous prime is 20001201193. The next prime is 20001201223. The reversal of 20001201221 is 12210210002.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20001201221 - 2²² = 19997006917 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20001201223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52358975 + ... + 52359356.

It is an arithmetic number, because the mean of its divisors is an integer number (5026479936).

Almost surely, 2^20001201221 is an apocalyptic number.

It is an amenable number.

20001201221 is a deficient number, since it is larger than the sum of its proper divisors (104718523).

20001201221 is a wasteful number, since it uses less digits than its factorization.

20001201221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104718522.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 20001201221 its reverse (12210210002), we get a palindrome (32211411223).

The spelling of 20001201221 in words is "twenty billion, one million, two hundred one thousand, two hundred twenty-one".