2123120309 has 2 divisors, whose sum is σ = 2123120310. Its totient is φ = 2123120308.

The previous prime is 2123120243. The next prime is 2123120359. The reversal of 2123120309 is 9030213212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1299602500 + 823517809 = 36050^2 + 28697^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2123120309 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2123120359) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1061560154 + 1061560155.

It is an arithmetic number, because the mean of its divisors is an integer number (1061560155).

Almost surely, 2^2123120309 is an apocalyptic number.

It is an amenable number.

2123120309 is a deficient number, since it is larger than the sum of its proper divisors (1).

2123120309 is an equidigital number, since it uses as much as digits as its factorization.

2123120309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 2123120309 is about 46077.3296643805. The cubic root of 2123120309 is about 1285.2616078267.

The spelling of 2123120309 in words is "two billion, one hundred twenty-three million, one hundred twenty thousand, three hundred nine".