18334185781 has 2 divisors, whose sum is σ = 18334185782. Its totient is φ = 18334185780.

The previous prime is 18334185761. The next prime is 18334185811. The reversal of 18334185781 is 18758143381.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18164300625 + 169885156 = 134775^2 + 13034^2 .

It is a cyclic number.

It is not a de Polignac number, because 18334185781 - 2⁹ = 18334185269 is a prime.

It is a super-2 number, since 2×18334185781² (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 (18334185761) 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, 9167092890 + 9167092891.

It is an arithmetic number, because the mean of its divisors is an integer number (9167092891).

Almost surely, 2^18334185781 is an apocalyptic number.

It is an amenable number.

18334185781 is a deficient number, since it is larger than the sum of its proper divisors (1).

18334185781 is an equidigital number, since it uses as much as digits as its factorization.

18334185781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 645120, while the sum is 49.

The spelling of 18334185781 in words is "eighteen billion, three hundred thirty-four million, one hundred eighty-five thousand, seven hundred eighty-one".