1815823 has 2 divisors, whose sum is σ = 1815824. Its totient is φ = 1815822.

The previous prime is 1815817. The next prime is 1815839. The reversal of 1815823 is 3285181.

It is a weak prime.

It is an emirp because it is prime and its reverse (3285181) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1815823 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1815791 and 1815800.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1815883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 907911 + 907912.

It is an arithmetic number, because the mean of its divisors is an integer number (907912).

2^1815823 is an apocalyptic number.

1815823 is a deficient number, since it is larger than the sum of its proper divisors (1).

1815823 is an equidigital number, since it uses as much as digits as its factorization.

1815823 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1920, while the sum is 28.

The square root of 1815823 is about 1347.5247678614. The cubic root of 1815823 is about 121.9994401121. Note that the first 3 decimals are identical.

It can be divided in two parts, 18158 and 23, that added together give a palindrome (18181).

The spelling of 1815823 in words is "one million, eight hundred fifteen thousand, eight hundred twenty-three".