1816813 has 2 divisors, whose sum is σ = 1816814. Its totient is φ = 1816812.

The previous prime is 1816783. The next prime is 1816831. The reversal of 1816813 is 3186181.

It is a happy number.

Together with next prime (1816831) 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., 1790244 + 26569 = 1338^2 + 163^2 .

It is a cyclic number.

It is not a de Polignac number, because 1816813 - 2⁹ = 1816301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1816853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 908406 + 908407.

It is an arithmetic number, because the mean of its divisors is an integer number (908407).

2^1816813 is an apocalyptic number.

It is an amenable number.

1816813 is a deficient number, since it is larger than the sum of its proper divisors (1).

1816813 is an equidigital number, since it uses as much as digits as its factorization.

1816813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1152, while the sum is 28.

The square root of 1816813 is about 1347.8920579928. The cubic root of 1816813 is about 122.0216077467.

It can be divided in two parts, 18168 and 13, that added together give a palindrome (18181).

The spelling of 1816813 in words is "one million, eight hundred sixteen thousand, eight hundred thirteen".