521564 has 12 divisors (see below), whose sum is σ = 922488. Its totient is φ = 258000.

The previous prime is 521557. The next prime is 521567. The reversal of 521564 is 465125.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521567) by changing a digit.

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, 242 + ... + 1049.

It is an arithmetic number, because the mean of its divisors is an integer number (76874).

2⁵²¹⁵⁶⁴ is an apocalyptic number.

It is an amenable number.

521564 is a deficient number, since it is larger than the sum of its proper divisors (400924).

521564 is a wasteful number, since it uses less digits than its factorization.

521564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1396 (or 1394 counting only the distinct ones).

The product of its digits is 1200, while the sum is 23.

The square root of 521564 is about 722.1938797858. The cubic root of 521564 is about 80.4950551854.

Adding to 521564 its reverse (465125), we get a palindrome (986689).

The spelling of 521564 in words is "five hundred twenty-one thousand, five hundred sixty-four".