217825 has 6 divisors (see below), whose sum is σ = 270134. Its totient is φ = 174240.

The previous prime is 217823. The next prime is 217829. The reversal of 217825 is 528712.

217825 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 61009 + 156816 = 247^2 + 396^2 .

It is not a de Polignac number, because 217825 - 2¹ = 217823 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25), and also a Moran number because the ratio is a prime number: 8713 = 217825 / (2 + 1 + 7 + 8 + 2 + 5).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 217825.

It is not an unprimeable number, because it can be changed into a prime (217823) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4332 + ... + 4381.

2²¹⁷⁸²⁵ is an apocalyptic number.

217825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

217825 is a deficient number, since it is larger than the sum of its proper divisors (52309).

217825 is an equidigital number, since it uses as much as digits as its factorization.

217825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8723 (or 8718 counting only the distinct ones).

The product of its digits is 1120, while the sum is 25.

The square root of 217825 is about 466.7172591623. The cubic root of 217825 is about 60.1685077905.

The spelling of 217825 in words is "two hundred seventeen thousand, eight hundred twenty-five".