521601 has 4 divisors (see below), whose sum is σ = 695472. Its totient is φ = 347732.

The previous prime is 521581. The next prime is 521603. The reversal of 521601 is 106125.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 521601 - 2⁶ = 521537 is a prime.

It is a D-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 (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 86931 + ... + 86936.

It is an arithmetic number, because the mean of its divisors is an integer number (173868).

2⁵²¹⁶⁰¹ is an apocalyptic number.

It is an amenable number.

521601 is a deficient number, since it is larger than the sum of its proper divisors (173871).

521601 is a wasteful number, since it uses less digits than its factorization.

521601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173870.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 521601 is about 722.2194957213. The cubic root of 521601 is about 80.4969585930.

Adding to 521601 its reverse (106125), we get a palindrome (627726).

It can be divided in two parts, 52 and 1601, that added together give a triangular number (1653 = T₅₇).

The spelling of 521601 in words is "five hundred twenty-one thousand, six hundred one".