505845 has 20 divisors (see below), whose sum is σ = 907500. Its totient is φ = 269568.

The previous prime is 505823. The next prime is 505867. The reversal of 505845 is 548505.

It is an interprime number because it is at equal distance from previous prime (505823) and next prime (505867).

It can be written as a sum of positive squares in 2 ways, for example, as 194481 + 311364 = 441^2 + 558^2 .

It is not a de Polignac number, because 505845 - 2⁶ = 505781 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 220 + ... + 1029.

It is an arithmetic number, because the mean of its divisors is an integer number (45375).

2⁵⁰⁵⁸⁴⁵ is an apocalyptic number.

It is an amenable number.

505845 is a deficient number, since it is larger than the sum of its proper divisors (401655).

505845 is a wasteful number, since it uses less digits than its factorization.

505845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1266 (or 1257 counting only the distinct ones).

The product of its (nonzero) digits is 4000, while the sum is 27.

The square root of 505845 is about 711.2278116047. The cubic root of 505845 is about 79.6781338473.

The spelling of 505845 in words is "five hundred five thousand, eight hundred forty-five".