825021 has 18 divisors (see below), whose sum is σ = 1245530. Its totient is φ = 526176.

The previous prime is 825017. The next prime is 825029. The reversal of 825021 is 120528.

It can be written as a sum of positive squares in 3 ways, for example, as 202500 + 622521 = 450^2 + 789^2 .

It is not a de Polignac number, because 825021 - 2² = 825017 is a prime.

It is a Duffinian number.

825021 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 824985 and 825003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (825029) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 7515 + ... + 7623.

2⁸²⁵⁰²¹ is an apocalyptic number.

It is an amenable number.

825021 is a deficient number, since it is larger than the sum of its proper divisors (420509).

825021 is a wasteful number, since it uses less digits than its factorization.

825021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173 (or 141 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 825021 is about 908.3066662752. The cubic root of 825021 is about 93.7896685460.

Adding to 825021 its reverse (120528), we get a palindrome (945549).

The spelling of 825021 in words is "eight hundred twenty-five thousand, twenty-one".