521613 has 8 divisors (see below), whose sum is σ = 772800. Its totient is φ = 347724.

The previous prime is 521603. The next prime is 521641. The reversal of 521613 is 316125.

521613 is a `hidden beast` number, since 52 + 1 + 613 = 666.

It is not a de Polignac number, because 521613 - 2⁵ = 521581 is a prime.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521603) 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 7 ways as a sum of consecutive naturals, for example, 9633 + ... + 9686.

It is an arithmetic number, because the mean of its divisors is an integer number (96600).

2⁵²¹⁶¹³ is an apocalyptic number.

It is an amenable number.

521613 is a deficient number, since it is larger than the sum of its proper divisors (251187).

521613 is a wasteful number, since it uses less digits than its factorization.

521613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19328 (or 19322 counting only the distinct ones).

The product of its digits is 180, while the sum is 18.

The square root of 521613 is about 722.2278033972. The cubic root of 521613 is about 80.4975758950.

Adding to 521613 its reverse (316125), we get a palindrome (837738).

The spelling of 521613 in words is "five hundred twenty-one thousand, six hundred thirteen".