218525 has 6 divisors (see below), whose sum is σ = 271002. Its totient is φ = 174800.

The previous prime is 218521. The next prime is 218527. The reversal of 218525 is 525812.

It can be written as a sum of positive squares in 3 ways, for example, as 1369 + 217156 = 37^2 + 466^2 .

It is not a de Polignac number, because 218525 - 2² = 218521 is a prime.

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

It is a Duffinian number.

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 218525.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4346 + ... + 4395.

It is an arithmetic number, because the mean of its divisors is an integer number (45167).

2²¹⁸⁵²⁵ is an apocalyptic number.

218525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

218525 is a deficient number, since it is larger than the sum of its proper divisors (52477).

218525 is an equidigital number, since it uses as much as digits as its factorization.

218525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8751 (or 8746 counting only the distinct ones).

The product of its digits is 800, while the sum is 23.

The square root of 218525 is about 467.4665763453. The cubic root of 218525 is about 60.2328911552.

The spelling of 218525 in words is "two hundred eighteen thousand, five hundred twenty-five".