18202018181 has 2 divisors, whose sum is σ = 18202018182. Its totient is φ = 18202018180.

The previous prime is 18202018151. The next prime is 18202018193. The reversal of 18202018181 is 18181020281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14880340225 + 3321677956 = 121985^2 + 57634^2 .

It is a cyclic number.

It is not a de Polignac number, because 18202018181 - 2⁶ = 18202018117 is a prime.

It is a super-2 number, since 2×18202018181² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18202018151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9101009090 + 9101009091.

It is an arithmetic number, because the mean of its divisors is an integer number (9101009091).

Almost surely, 2^18202018181 is an apocalyptic number.

It is an amenable number.

18202018181 is a deficient number, since it is larger than the sum of its proper divisors (1).

18202018181 is an equidigital number, since it uses as much as digits as its factorization.

18202018181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2048, while the sum is 32.

The spelling of 18202018181 in words is "eighteen billion, two hundred two million, eighteen thousand, one hundred eighty-one".