213221020121 has 2 divisors, whose sum is σ = 213221020122. Its totient is φ = 213221020120.

The previous prime is 213221020049. The next prime is 213221020169. The reversal of 213221020121 is 121020122312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 213041326096 + 179694025 = 461564^2 + 13405^2 .

It is a cyclic number.

It is not a de Polignac number, because 213221020121 - 2³⁴ = 196041150937 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 213221020121.

It is not a weakly prime, because it can be changed into another prime (213221020721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106610510060 + 106610510061.

It is an arithmetic number, because the mean of its divisors is an integer number (106610510061).

Almost surely, 2^213221020121 is an apocalyptic number.

It is an amenable number.

213221020121 is a deficient number, since it is larger than the sum of its proper divisors (1).

213221020121 is an equidigital number, since it uses as much as digits as its factorization.

213221020121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 213221020121 its reverse (121020122312), we get a palindrome (334241142433).

The spelling of 213221020121 in words is "two hundred thirteen billion, two hundred twenty-one million, twenty thousand, one hundred twenty-one".