21221220221101 has 4 divisors (see below), whose sum is σ = 21223444910400. Its totient is φ = 21218995531804.

The previous prime is 21221220221041. The next prime is 21221220221129. The reversal of 21221220221101 is 10112202212212.

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 21221220221101 - 2⁹ = 21221220220589 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 (21221220221171) 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, 1112330341 + ... + 1112349418.

It is an arithmetic number, because the mean of its divisors is an integer number (5305861227600).

Almost surely, 2^{21221220221101} is an apocalyptic number.

It is an amenable number.

21221220221101 is a deficient number, since it is larger than the sum of its proper divisors (2224689299).

21221220221101 is an equidigital number, since it uses as much as digits as its factorization.

21221220221101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2224689298.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21221220221101 its reverse (10112202212212), we get a palindrome (31333422433313).

The spelling of 21221220221101 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred twenty million, two hundred twenty-one thousand, one hundred one".