2123456261 has 2 divisors, whose sum is σ = 2123456262. Its totient is φ = 2123456260.

The previous prime is 2123456227. The next prime is 2123456303. The reversal of 2123456261 is 1626543212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2076533761 + 46922500 = 45569^2 + 6850^2 .

It is a cyclic number.

It is not a de Polignac number, because 2123456261 - 2¹⁰ = 2123455237 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2123456201) 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, 1061728130 + 1061728131.

It is an arithmetic number, because the mean of its divisors is an integer number (1061728131).

Almost surely, 2^2123456261 is an apocalyptic number.

It is an amenable number.

2123456261 is a deficient number, since it is larger than the sum of its proper divisors (1).

2123456261 is an equidigital number, since it uses as much as digits as its factorization.

2123456261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17280, while the sum is 32.

The square root of 2123456261 is about 46080.9750439376. The cubic root of 2123456261 is about 1285.3293953866.

Adding to 2123456261 its reverse (1626543212), we get a palindrome (3749999473).

The spelling of 2123456261 in words is "two billion, one hundred twenty-three million, four hundred fifty-six thousand, two hundred sixty-one".