521985 has 32 divisors (see below), whose sum is σ = 933120. Its totient is φ = 247808.

The previous prime is 521981. The next prime is 521993. The reversal of 521985 is 589125.

It is a cyclic number.

It is not a de Polignac number, because 521985 - 2² = 521981 is a prime.

521985 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (521981) by changing a digit.

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

It is an upside-down number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5821 + ... + 5909.

It is an arithmetic number, because the mean of its divisors is an integer number (29160).

2⁵²¹⁹⁸⁵ is an apocalyptic number.

It is an amenable number.

521985 is a deficient number, since it is larger than the sum of its proper divisors (411135).

521985 is a wasteful number, since it uses less digits than its factorization.

521985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137.

The product of its digits is 3600, while the sum is 30.

The square root of 521985 is about 722.4852939680. The cubic root of 521985 is about 80.5167075644.

The spelling of 521985 in words is "five hundred twenty-one thousand, nine hundred eighty-five".