521504 has 24 divisors (see below), whose sum is σ = 1053360. Its totient is φ = 254016.

The previous prime is 521503. The next prime is 521519. The reversal of 521504 is 405125.

It is a zygodrome in base 3.

It is not an unprimeable number, because it can be changed into a prime (521503) 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, 1187 + ... + 1565.

It is an arithmetic number, because the mean of its divisors is an integer number (43890).

2⁵²¹⁵⁰⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 521504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (526680).

521504 is an abundant number, since it is smaller than the sum of its proper divisors (531856).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

521504 is a wasteful number, since it uses less digits than its factorization.

521504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432 (or 424 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 17.

The square root of 521504 is about 722.1523384993. The cubic root of 521504 is about 80.4919683871.

Adding to 521504 its reverse (405125), we get a palindrome (926629).

The spelling of 521504 in words is "five hundred twenty-one thousand, five hundred four".