2818181 has 2 divisors, whose sum is σ = 2818182. Its totient is φ = 2818180.

The previous prime is 2818171. The next prime is 2818219. The reversal of 2818181 is 1818182.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2669956 + 148225 = 1634^2 + 385^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2818181 is a prime.

It is a super-2 number, since 2×2818181² = 15884288297522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen 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 (2818111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1409090 + 1409091.

It is an arithmetic number, because the mean of its divisors is an integer number (1409091).

2^2818181 is an apocalyptic number.

It is an amenable number.

2818181 is a deficient number, since it is larger than the sum of its proper divisors (1).

2818181 is an equidigital number, since it uses as much as digits as its factorization.

2818181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1024, while the sum is 29.

The square root of 2818181 is about 1678.7438756404. The cubic root of 2818181 is about 141.2503808693.

Subtracting from 2818181 its reverse (1818182), we obtain a palindrome (999999).

The spelling of 2818181 in words is "two million, eight hundred eighteen thousand, one hundred eighty-one".