825509 has 2 divisors, whose sum is σ = 825510. Its totient is φ = 825508.

The previous prime is 825491. The next prime is 825527. The reversal of 825509 is 905528.

It is a balanced prime because it is at equal distance from previous prime (825491) and next prime (825527).

It can be written as a sum of positive squares in only one way, i.e., 748225 + 77284 = 865^2 + 278^2 .

It is a cyclic number.

It is not a de Polignac number, because 825509 - 2¹⁶ = 759973 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is an Ulam number.

It is a Curzon number.

It is a plaindrome in base 15.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (825109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 412754 + 412755.

It is an arithmetic number, because the mean of its divisors is an integer number (412755).

2⁸²⁵⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

825509 is a deficient number, since it is larger than the sum of its proper divisors (1).

825509 is an equidigital number, since it uses as much as digits as its factorization.

825509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3600, while the sum is 29.

The square root of 825509 is about 908.5752583028. The cubic root of 825509 is about 93.8081571004.

The spelling of 825509 in words is "eight hundred twenty-five thousand, five hundred nine".