221825 has 12 divisors (see below), whose sum is σ = 290160. Its totient is φ = 167760.

The previous prime is 221813. The next prime is 221827. The reversal of 221825 is 528122.

It is not a de Polignac number, because 221825 - 2¹⁴ = 205441 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221797 and 221806.

It is not an unprimeable number, because it can be changed into a prime (221827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 242 + ... + 708.

It is an arithmetic number, because the mean of its divisors is an integer number (24180).

2²²¹⁸²⁵ is an apocalyptic number.

221825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

221825 is a deficient number, since it is larger than the sum of its proper divisors (68335).

221825 is a wasteful number, since it uses less digits than its factorization.

221825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 496 (or 491 counting only the distinct ones).

The product of its digits is 320, while the sum is 20.

The square root of 221825 is about 470.9830145557. The cubic root of 221825 is about 60.5345748687.

Adding to 221825 its reverse (528122), we get a palindrome (749947).

The spelling of 221825 in words is "two hundred twenty-one thousand, eight hundred twenty-five".