220001212121 has 2 divisors, whose sum is σ = 220001212122. Its totient is φ = 220001212120.

The previous prime is 220001212117. The next prime is 220001212169. The reversal of 220001212121 is 121212100022.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 219778128025 + 223084096 = 468805^2 + 14936^2 .

It is a cyclic number.

It is not a de Polignac number, because 220001212121 - 2² = 220001212117 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 220001212096 and 220001212105.

It is not a weakly prime, because it can be changed into another prime (220001212721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110000606060 + 110000606061.

It is an arithmetic number, because the mean of its divisors is an integer number (110000606061).

Almost surely, 2^220001212121 is an apocalyptic number.

It is an amenable number.

220001212121 is a deficient number, since it is larger than the sum of its proper divisors (1).

220001212121 is an equidigital number, since it uses as much as digits as its factorization.

220001212121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 220001212121 its reverse (121212100022), we get a palindrome (341213312143).

The spelling of 220001212121 in words is "two hundred twenty billion, one million, two hundred twelve thousand, one hundred twenty-one".