525509 has 4 divisors (see below), whose sum is σ = 543660. Its totient is φ = 507360.

The previous prime is 525493. The next prime is 525517. The reversal of 525509 is 905525.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 228484 + 297025 = 478^2 + 545^2 .

It is a cyclic number.

It is not a de Polignac number, because 525509 - 2⁴ = 525493 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (525529) 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, 9032 + ... + 9089.

It is an arithmetic number, because the mean of its divisors is an integer number (135915).

2⁵²⁵⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

525509 is a deficient number, since it is larger than the sum of its proper divisors (18151).

525509 is a wasteful number, since it uses less digits than its factorization.

525509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18150.

The product of its (nonzero) digits is 2250, while the sum is 26.

The square root of 525509 is about 724.9199955857. The cubic root of 525509 is about 80.6974948384.

The spelling of 525509 in words is "five hundred twenty-five thousand, five hundred nine".