18236423173 has 2 divisors, whose sum is σ = 18236423174. Its totient is φ = 18236423172.

The previous prime is 18236423131. The next prime is 18236423189. The reversal of 18236423173 is 37132463281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13989685284 + 4246737889 = 118278^2 + 65167^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18236423173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18236423273) 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, 9118211586 + 9118211587.

It is an arithmetic number, because the mean of its divisors is an integer number (9118211587).

Almost surely, 2^18236423173 is an apocalyptic number.

It is an amenable number.

18236423173 is a deficient number, since it is larger than the sum of its proper divisors (1).

18236423173 is an equidigital number, since it uses as much as digits as its factorization.

18236423173 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145152, while the sum is 40.

The spelling of 18236423173 in words is "eighteen billion, two hundred thirty-six million, four hundred twenty-three thousand, one hundred seventy-three".