505218 has 32 divisors (see below), whose sum is σ = 1207296. Its totient is φ = 137808.

The previous prime is 505213. The next prime is 505231. The reversal of 505218 is 812505.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an alternating number because its digits alternate between odd and even.

It is a junction number, because it is equal to n+sod(n) for n = 505194 and 505203.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 505218.

It is not an unprimeable number, because it can be changed into a prime (505213) by changing a digit.

505218 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 705 + ... + 1227.

It is an arithmetic number, because the mean of its divisors is an integer number (37728).

2⁵⁰⁵²¹⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 505218, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (603648).

505218 is an abundant number, since it is smaller than the sum of its proper divisors (702078).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

505218 is a wasteful number, since it uses less digits than its factorization.

505218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 558.

The product of its (nonzero) digits is 400, while the sum is 21.

The square root of 505218 is about 710.7868878926. The cubic root of 505218 is about 79.6451996182.

The spelling of 505218 in words is "five hundred five thousand, two hundred eighteen".