1665823 has 2 divisors, whose sum is σ = 1665824. Its totient is φ = 1665822.

The previous prime is 1665767. The next prime is 1665827. The reversal of 1665823 is 3285661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1665823 - 2⁹ = 1665311 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1665827) by changing a digit.

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

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832911 + 832912.

It is an arithmetic number, because the mean of its divisors is an integer number (832912).

2^1665823 is an apocalyptic number.

1665823 is a deficient number, since it is larger than the sum of its proper divisors (1).

1665823 is an equidigital number, since it uses as much as digits as its factorization.

1665823 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8640, while the sum is 31.

The square root of 1665823 is about 1290.6676566801. The cubic root of 1665823 is about 118.5431012243.

The spelling of 1665823 in words is "one million, six hundred sixty-five thousand, eight hundred twenty-three".