825521 has 4 divisors (see below), whose sum is σ = 831600. Its totient is φ = 819444.

The previous prime is 825509. The next prime is 825527. The reversal of 825521 is 125528.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 825521 - 2¹⁰ = 824497 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 825521.

It is not an unprimeable number, because it can be changed into a prime (825527) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2831 + ... + 3108.

It is an arithmetic number, because the mean of its divisors is an integer number (207900).

2⁸²⁵⁵²¹ is an apocalyptic number.

It is an amenable number.

825521 is a deficient number, since it is larger than the sum of its proper divisors (6079).

825521 is a wasteful number, since it uses less digits than its factorization.

825521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6078.

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

The square root of 825521 is about 908.5818620246. The cubic root of 825521 is about 93.8086116452.

The spelling of 825521 in words is "eight hundred twenty-five thousand, five hundred twenty-one".