521864 has 16 divisors (see below), whose sum is σ = 1118400. Its totient is φ = 223632.

The previous prime is 521861. The next prime is 521869. The reversal of 521864 is 468125.

It is not an unprimeable number, because it can be changed into a prime (521861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4604 + ... + 4715.

It is an arithmetic number, because the mean of its divisors is an integer number (69900).

2⁵²¹⁸⁶⁴ is an apocalyptic number.

It is an amenable number.

521864 is an abundant number, since it is smaller than the sum of its proper divisors (596536).

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

521864 is a wasteful number, since it uses less digits than its factorization.

521864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9332 (or 9328 counting only the distinct ones).

The product of its digits is 1920, while the sum is 26.

The square root of 521864 is about 722.4015503859. The cubic root of 521864 is about 80.5104856267.

Adding to 521864 its reverse (468125), we get a palindrome (989989).

The spelling of 521864 in words is "five hundred twenty-one thousand, eight hundred sixty-four".