821025 has 36 divisors (see below), whose sum is σ = 1523340. Its totient is φ = 422400.

The previous prime is 821003. The next prime is 821027. The reversal of 821025 is 520128.

It can be written as a sum of positive squares in 6 ways, for example, as 254016 + 567009 = 504^2 + 753^2 .

It is not a de Polignac number, because 821025 - 2¹¹ = 818977 is a prime.

It is a Curzon number.

It is a nialpdrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 820989 and 821007.

It is not an unprimeable number, because it can be changed into a prime (821027) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 9181 + ... + 9269.

It is an arithmetic number, because the mean of its divisors is an integer number (42315).

2⁸²¹⁰²⁵ is an apocalyptic number.

It is an amenable number.

821025 is a deficient number, since it is larger than the sum of its proper divisors (702315).

821025 is a wasteful number, since it uses less digits than its factorization.

821025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146 (or 138 counting only the distinct ones).

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

The square root of 821025 is about 906.1042986323. The cubic root of 821025 is about 93.6379995830.

The spelling of 821025 in words is "eight hundred twenty-one thousand, twenty-five".