2121223121 has 2 divisors, whose sum is σ = 2121223122. Its totient is φ = 2121223120.

The previous prime is 2121223103. The next prime is 2121223141. The reversal of 2121223121 is 1213221212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1738473025 + 382750096 = 41695^2 + 19564^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121223121 - 2⁶ = 2121223057 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2121223121.

It is not a weakly prime, because it can be changed into another prime (2121223141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060611560 + 1060611561.

It is an arithmetic number, because the mean of its divisors is an integer number (1060611561).

Almost surely, 2^2121223121 is an apocalyptic number.

It is an amenable number.

2121223121 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121223121 is an equidigital number, since it uses as much as digits as its factorization.

2121223121 is an evil number, because the sum of its binary digits is even.

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

The square root of 2121223121 is about 46056.7380629588. The cubic root of 2121223121 is about 1284.8786636682.

Adding to 2121223121 its reverse (1213221212), we get a palindrome (3334444333).

The spelling of 2121223121 in words is "two billion, one hundred twenty-one million, two hundred twenty-three thousand, one hundred twenty-one".