20211201201221 has 4 divisors (see below), whose sum is σ = 20495866006944. Its totient is φ = 19926536395500.

The previous prime is 20211201201211. The next prime is 20211201201353. The reversal of 20211201201221 is 12210210211202.

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 a de Polignac number, because none of the positive numbers 2^k-20211201201221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20211201201221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20211201201211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 142332402755 + ... + 142332402896.

It is an arithmetic number, because the mean of its divisors is an integer number (5123966501736).

Almost surely, 2^{20211201201221} is an apocalyptic number.

It is an amenable number.

20211201201221 is a deficient number, since it is larger than the sum of its proper divisors (284664805723).

20211201201221 is an equidigital number, since it uses as much as digits as its factorization.

20211201201221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284664805722.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 20211201201221 its reverse (12210210211202), we get a palindrome (32421411412423).

The spelling of 20211201201221 in words is "twenty trillion, two hundred eleven billion, two hundred one million, two hundred one thousand, two hundred twenty-one".