221210404012121 has 2 divisors, whose sum is σ = 221210404012122. Its totient is φ = 221210404012120.

The previous prime is 221210404012093. The next prime is 221210404012151. The reversal of 221210404012121 is 121210404012122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 164496913153225 + 56713490858896 = 12825635^2 + 7530836^2 .

It is a cyclic number.

It is not a de Polignac number, because 221210404012121 - 2⁴² = 216812357501017 is a prime.

It is a super-2 number, since 2×221210404012121² (a number of 29 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (221210404012151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110605202006060 + 110605202006061.

It is an arithmetic number, because the mean of its divisors is an integer number (110605202006061).

Almost surely, 2^{221210404012121} is an apocalyptic number.

It is an amenable number.

221210404012121 is a deficient number, since it is larger than the sum of its proper divisors (1).

221210404012121 is an equidigital number, since it uses as much as digits as its factorization.

221210404012121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 512, while the sum is 23.

Adding to 221210404012121 its reverse (121210404012122), we get a palindrome (342420808024243).

Subtracting from 221210404012121 its reverse (121210404012122), we obtain a palindrome (99999999999999).

The spelling of 221210404012121 in words is "two hundred twenty-one trillion, two hundred ten billion, four hundred four million, twelve thousand, one hundred twenty-one".