123666689 has 2 divisors, whose sum is σ = 123666690. Its totient is φ = 123666688.

The previous prime is 123666677. The next prime is 123666707. The reversal of 123666689 is 986666321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 121000000 + 2666689 = 11000^2 + 1633^2 .

It is a cyclic number.

It is not a de Polignac number, because 123666689 - 2²⁴ = 106889473 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a plaindrome in base 10.

It is not a weakly prime, because it can be changed into another prime (123666659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61833344 + 61833345.

It is an arithmetic number, because the mean of its divisors is an integer number (61833345).

Almost surely, 2^123666689 is an apocalyptic number.

It is an amenable number.

123666689 is a deficient number, since it is larger than the sum of its proper divisors (1).

123666689 is an equidigital number, since it uses as much as digits as its factorization.

123666689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 559872, while the sum is 47.

The square root of 123666689 is about 11120.5525492216. The cubic root of 123666689 is about 498.2158934998.

The spelling of 123666689 in words is "one hundred twenty-three million, six hundred sixty-six thousand, six hundred eighty-nine".