505643 has 2 divisors, whose sum is σ = 505644. Its totient is φ = 505642.

The previous prime is 505639. The next prime is 505657. The reversal of 505643 is 346505.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 505643 - 2² = 505639 is a prime.

It is not a weakly prime, because it can be changed into another prime (505613) 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, 252821 + 252822.

It is an arithmetic number, because the mean of its divisors is an integer number (252822).

2⁵⁰⁵⁶⁴³ is an apocalyptic number.

505643 is a deficient number, since it is larger than the sum of its proper divisors (1).

505643 is an equidigital number, since it uses as much as digits as its factorization.

505643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1800, while the sum is 23.

The square root of 505643 is about 711.0857894797. The cubic root of 505643 is about 79.6675264307.

The spelling of 505643 in words is "five hundred five thousand, six hundred forty-three".