18344501809 has 2 divisors, whose sum is σ = 18344501810. Its totient is φ = 18344501808.

The previous prime is 18344501807. The next prime is 18344501849. The reversal of 18344501809 is 90810544381.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13346718784 + 4997783025 = 115528^2 + 70695^2 .

It is a cyclic number.

It is not a de Polignac number, because 18344501809 - 2¹ = 18344501807 is a prime.

Together with 18344501807, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (18344501807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9172250904 + 9172250905.

It is an arithmetic number, because the mean of its divisors is an integer number (9172250905).

Almost surely, 2^18344501809 is an apocalyptic number.

It is an amenable number.

18344501809 is a deficient number, since it is larger than the sum of its proper divisors (1).

18344501809 is an equidigital number, since it uses as much as digits as its factorization.

18344501809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 138240, while the sum is 43.

The spelling of 18344501809 in words is "eighteen billion, three hundred forty-four million, five hundred one thousand, eight hundred nine".