1811923 has 2 divisors, whose sum is σ = 1811924. Its totient is φ = 1811922.

The previous prime is 1811903. The next prime is 1811939. The reversal of 1811923 is 3291181.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1811923 is a prime.

1811923 is a lucky number.

It is equal to p₁₃₅₉₀₇ and since 1811923 and 135907 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (1811903) 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, 905961 + 905962.

It is an arithmetic number, because the mean of its divisors is an integer number (905962).

2^1811923 is an apocalyptic number.

1811923 is a deficient number, since it is larger than the sum of its proper divisors (1).

1811923 is an equidigital number, since it uses as much as digits as its factorization.

1811923 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 432, while the sum is 25.

The square root of 1811923 is about 1346.0768923059. The cubic root of 1811923 is about 121.9120345921.

The spelling of 1811923 in words is "one million, eight hundred eleven thousand, nine hundred twenty-three".