2221121112121 has 2 divisors, whose sum is σ = 2221121112122. Its totient is φ = 2221121112120.

The previous prime is 2221121112113. The next prime is 2221121112127. The reversal of 2221121112121 is 1212111211222.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1422664490025 + 798456622096 = 1192755^2 + 893564^2 .

It is a cyclic number.

It is not a de Polignac number, because 2221121112121 - 2³ = 2221121112113 is a prime.

It is not a weakly prime, because it can be changed into another prime (2221121112127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1110560556060 + 1110560556061.

It is an arithmetic number, because the mean of its divisors is an integer number (1110560556061).

Almost surely, 2^{2221121112121} is an apocalyptic number.

It is an amenable number.

2221121112121 is a deficient number, since it is larger than the sum of its proper divisors (1).

2221121112121 is an equidigital number, since it uses as much as digits as its factorization.

2221121112121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 64, while the sum is 19.

Adding to 2221121112121 its reverse (1212111211222), we get a palindrome (3433232323343).

The spelling of 2221121112121 in words is "two trillion, two hundred twenty-one billion, one hundred twenty-one million, one hundred twelve thousand, one hundred twenty-one".