221220201222121 has 2 divisors, whose sum is σ = 221220201222122. Its totient is φ = 221220201222120.

The previous prime is 221220201222079. The next prime is 221220201222131. The reversal of 221220201222121 is 121222102022122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 200854512459225 + 20365688762896 = 14172315^2 + 4512836^2 .

It is a cyclic number.

It is not a de Polignac number, because 221220201222121 - 2¹³ = 221220201213929 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221220201222092 and 221220201222101.

It is not a weakly prime, because it can be changed into another prime (221220201222131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110610100611060 + 110610100611061.

It is an arithmetic number, because the mean of its divisors is an integer number (110610100611061).

Almost surely, 2^{221220201222121} is an apocalyptic number.

It is an amenable number.

221220201222121 is a deficient number, since it is larger than the sum of its proper divisors (1).

221220201222121 is an equidigital number, since it uses as much as digits as its factorization.

221220201222121 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 22.

Adding to 221220201222121 its reverse (121222102022122), we get a palindrome (342442303244243).

The spelling of 221220201222121 in words is "two hundred twenty-one trillion, two hundred twenty billion, two hundred one million, two hundred twenty-two thousand, one hundred twenty-one".