2123123291 has 2 divisors, whose sum is σ = 2123123292. Its totient is φ = 2123123290.

The previous prime is 2123123287. The next prime is 2123123311. The reversal of 2123123291 is 1923213212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2123123291 - 2² = 2123123287 is a prime.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2123123291.

It is not a weakly prime, because it can be changed into another prime (2123123221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1061561645 + 1061561646.

It is an arithmetic number, because the mean of its divisors is an integer number (1061561646).

Almost surely, 2^2123123291 is an apocalyptic number.

2123123291 is a deficient number, since it is larger than the sum of its proper divisors (1).

2123123291 is an equidigital number, since it uses as much as digits as its factorization.

2123123291 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1296, while the sum is 26.

The square root of 2123123291 is about 46077.3620230152. The cubic root of 2123123291 is about 1285.2622095587.

The spelling of 2123123291 in words is "two billion, one hundred twenty-three million, one hundred twenty-three thousand, two hundred ninety-one".