505811 has 2 divisors, whose sum is σ = 505812. Its totient is φ = 505810.

The previous prime is 505781. The next prime is 505819. The reversal of 505811 is 118505.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 505811 - 2¹⁰ = 504787 is a prime.

It is not a weakly prime, because it can be changed into another prime (505819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 252905 + 252906.

It is an arithmetic number, because the mean of its divisors is an integer number (252906).

2⁵⁰⁵⁸¹¹ is an apocalyptic number.

505811 is a deficient number, since it is larger than the sum of its proper divisors (1).

505811 is an equidigital number, since it uses as much as digits as its factorization.

505811 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 200, while the sum is 20.

The square root of 505811 is about 711.2039088756. The cubic root of 505811 is about 79.6763486382.

The spelling of 505811 in words is "five hundred five thousand, eight hundred eleven".