2312121221 has 2 divisors, whose sum is σ = 2312121222. Its totient is φ = 2312121220.

The previous prime is 2312121209. The next prime is 2312121257. The reversal of 2312121221 is 1221212132.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1833124225 + 478996996 = 42815^2 + 21886^2 .

It is a cyclic number.

It is not a de Polignac number, because 2312121221 - 2¹⁰ = 2312120197 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 2312121221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2312121281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1156060610 + 1156060611.

It is an arithmetic number, because the mean of its divisors is an integer number (1156060611).

Almost surely, 2^2312121221 is an apocalyptic number.

It is an amenable number.

2312121221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2312121221 is an equidigital number, since it uses as much as digits as its factorization.

2312121221 is an odious number, because the sum of its binary digits is odd.

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

The square root of 2312121221 is about 48084.5216363852. The cubic root of 2312121221 is about 1322.3209131871.

Adding to 2312121221 its reverse (1221212132), we get a palindrome (3533333353).

The spelling of 2312121221 in words is "two billion, three hundred twelve million, one hundred twenty-one thousand, two hundred twenty-one".