18409954909 has 2 divisors, whose sum is σ = 18409954910. Its totient is φ = 18409954908.

The previous prime is 18409954907. The next prime is 18409954919. The reversal of 18409954909 is 90945990481.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18225810009 + 184144900 = 135003^2 + 13570^2 .

It is a cyclic number.

It is not a de Polignac number, because 18409954909 - 2¹ = 18409954907 is a prime.

Together with 18409954907, 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 (18409954907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9204977454 + 9204977455.

It is an arithmetic number, because the mean of its divisors is an integer number (9204977455).

Almost surely, 2^18409954909 is an apocalyptic number.

It is an amenable number.

18409954909 is a deficient number, since it is larger than the sum of its proper divisors (1).

18409954909 is an equidigital number, since it uses as much as digits as its factorization.

18409954909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4199040, while the sum is 58.

The spelling of 18409954909 in words is "eighteen billion, four hundred nine million, nine hundred fifty-four thousand, nine hundred nine".