21220102022221 has 4 divisors (see below), whose sum is σ = 21311175421692. Its totient is φ = 21129028622752.

The previous prime is 21220102022167. The next prime is 21220102022233. The reversal of 21220102022221 is 12222020102212.

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 2566436040100 + 18653665982121 = 1602010^2 + 4318989^2 .

It is a cyclic number.

It is not a de Polignac number, because 21220102022221 - 2¹³ = 21220102014029 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 (21220102022261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45536699386 + ... + 45536699851.

It is an arithmetic number, because the mean of its divisors is an integer number (5327793855423).

Almost surely, 2^{21220102022221} is an apocalyptic number.

It is an amenable number.

21220102022221 is a deficient number, since it is larger than the sum of its proper divisors (91073399471).

21220102022221 is an equidigital number, since it uses as much as digits as its factorization.

21220102022221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91073399470.

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 21220102022221 its reverse (12222020102212), we get a palindrome (33442122124433).

The spelling of 21220102022221 in words is "twenty-one trillion, two hundred twenty billion, one hundred two million, twenty-two thousand, two hundred twenty-one".