20110211201221 has 4 divisors (see below), whose sum is σ = 20110220227692. Its totient is φ = 20110202174752.

The previous prime is 20110211201209. The next prime is 20110211201251. The reversal of 20110211201221 is 12210211201102.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 11034687422500 + 9075523778721 = 3321850^2 + 3012561^2 .

It is a cyclic number.

It is not a de Polignac number, because 20110211201221 - 2¹⁷ = 20110211070149 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20110211201195 and 20110211201204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20110211201251) 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 3 ways as a sum of consecutive naturals, for example, 1493121 + ... + 6515353.

It is an arithmetic number, because the mean of its divisors is an integer number (5027555056923).

Almost surely, 2^{20110211201221} is an apocalyptic number.

It is an amenable number.

20110211201221 is a deficient number, since it is larger than the sum of its proper divisors (9026471).

20110211201221 is an equidigital number, since it uses as much as digits as its factorization.

20110211201221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9026470.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 20110211201221 its reverse (12210211201102), we get a palindrome (32320422402323).

The spelling of 20110211201221 in words is "twenty trillion, one hundred ten billion, two hundred eleven million, two hundred one thousand, two hundred twenty-one".