221020102020121 has 4 divisors (see below), whose sum is σ = 221125903890100. Its totient is φ = 220914300150144.

The previous prime is 221020102020119. The next prime is 221020102020181. The reversal of 221020102020121 is 121020201020122.

It is a happy number.

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 196735548800025 + 24284553220096 = 14026245^2 + 4927936^2 .

It is a cyclic number.

It is not a de Polignac number, because 221020102020121 - 2¹ = 221020102020119 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221020102020095 and 221020102020104.

It is not an unprimeable number, because it can be changed into a prime (221020102020101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52900931856 + ... + 52900936033.

It is an arithmetic number, because the mean of its divisors is an integer number (55281475972525).

Almost surely, 2^{221020102020121} is an apocalyptic number.

It is an amenable number.

221020102020121 is a deficient number, since it is larger than the sum of its proper divisors (105801869979).

221020102020121 is a wasteful number, since it uses less digits than its factorization.

221020102020121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105801869978.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 221020102020121 its reverse (121020201020122), we get a palindrome (342040303040243).

Subtracting from 221020102020121 its reverse (121020201020122), we obtain a palindrome (99999900999999).

The spelling of 221020102020121 in words is "two hundred twenty-one trillion, twenty billion, one hundred two million, twenty thousand, one hundred twenty-one".