18814585109 has 2 divisors, whose sum is σ = 18814585110. Its totient is φ = 18814585108.

The previous prime is 18814585091. The next prime is 18814585123. The reversal of 18814585109 is 90158541881.

Together with previous prime (18814585091) 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., 11912631025 + 6901954084 = 109145^2 + 83078^2 .

It is a cyclic number.

It is not a de Polignac number, because 18814585109 - 2¹² = 18814581013 is a prime.

It is a super-2 number, since 2×18814585109² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18814585159) 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, 9407292554 + 9407292555.

It is an arithmetic number, because the mean of its divisors is an integer number (9407292555).

Almost surely, 2^18814585109 is an apocalyptic number.

It is an amenable number.

18814585109 is a deficient number, since it is larger than the sum of its proper divisors (1).

18814585109 is an equidigital number, since it uses as much as digits as its factorization.

18814585109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 460800, while the sum is 50.

The spelling of 18814585109 in words is "eighteen billion, eight hundred fourteen million, five hundred eighty-five thousand, one hundred nine".