18123709 has 2 divisors, whose sum is σ = 18123710. Its totient is φ = 18123708.

The previous prime is 18123689. The next prime is 18123713. The reversal of 18123709 is 90732181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18020025 + 103684 = 4245^2 + 322^2 .

It is a cyclic number.

It is not a de Polignac number, because 18123709 - 2⁹ = 18123197 is a prime.

It is a plaindrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18123779) 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, 9061854 + 9061855.

It is an arithmetic number, because the mean of its divisors is an integer number (9061855).

Almost surely, 2^18123709 is an apocalyptic number.

It is an amenable number.

18123709 is a deficient number, since it is larger than the sum of its proper divisors (1).

18123709 is an equidigital number, since it uses as much as digits as its factorization.

18123709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 18123709 is about 4257.1949685209. The cubic root of 18123709 is about 262.6731568035.

The spelling of 18123709 in words is "eighteen million, one hundred twenty-three thousand, seven hundred nine".