18399673 has 2 divisors, whose sum is σ = 18399674. Its totient is φ = 18399672.

The previous prime is 18399637. The next prime is 18399691. The reversal of 18399673 is 37699381.

Together with previous prime (18399637) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12089529 + 6310144 = 3477^2 + 2512^2 .

It is an emirp because it is prime and its reverse (37699381) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18399673 - 2²¹ = 16302521 is a prime.

It is not a weakly prime, because it can be changed into another prime (18399973) 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, 9199836 + 9199837.

It is an arithmetic number, because the mean of its divisors is an integer number (9199837).

Almost surely, 2^18399673 is an apocalyptic number.

It is an amenable number.

18399673 is a deficient number, since it is larger than the sum of its proper divisors (1).

18399673 is an equidigital number, since it uses as much as digits as its factorization.

18399673 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 244944, while the sum is 46.

The square root of 18399673 is about 4289.4840016021. The cubic root of 18399673 is about 263.9996604296. Note that the first 3 decimals are identical.

It can be divided in two parts, 183 and 99673, that added together give a square (99856 = 316²).

The spelling of 18399673 in words is "eighteen million, three hundred ninety-nine thousand, six hundred seventy-three".