18744109 has 2 divisors, whose sum is σ = 18744110. Its totient is φ = 18744108.

The previous prime is 18744107. The next prime is 18744113. The reversal of 18744109 is 90144781.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18088009 + 656100 = 4253^2 + 810^2 .

It is an emirp because it is prime and its reverse (90144781) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18744109 - 2¹ = 18744107 is a prime.

Together with 18744107, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18744107) 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, 9372054 + 9372055.

It is an arithmetic number, because the mean of its divisors is an integer number (9372055).

Almost surely, 2^18744109 is an apocalyptic number.

It is an amenable number.

18744109 is a deficient number, since it is larger than the sum of its proper divisors (1).

18744109 is an equidigital number, since it uses as much as digits as its factorization.

18744109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 34.

The square root of 18744109 is about 4329.4467313965. The cubic root of 18744109 is about 265.6368166185.

The spelling of 18744109 in words is "eighteen million, seven hundred forty-four thousand, one hundred nine".