521684 has 12 divisors (see below), whose sum is σ = 935508. Its totient is φ = 254400.

The previous prime is 521671. The next prime is 521693. The reversal of 521684 is 486125.

It can be written as a sum of positive squares in 2 ways, for example, as 31684 + 490000 = 178^2 + 700^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1427 + ... + 1754.

It is an arithmetic number, because the mean of its divisors is an integer number (77959).

2⁵²¹⁶⁸⁴ is an apocalyptic number.

It is an amenable number.

521684 is a deficient number, since it is larger than the sum of its proper divisors (413824).

521684 is a wasteful number, since it uses less digits than its factorization.

521684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3226 (or 3224 counting only the distinct ones).

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

The square root of 521684 is about 722.2769551910. The cubic root of 521684 is about 80.5012280717.

The spelling of 521684 in words is "five hundred twenty-one thousand, six hundred eighty-four".