521336521 has 4 divisors (see below), whose sum is σ = 523260544. Its totient is φ = 519412500.

The previous prime is 521336513. The next prime is 521336539. The reversal of 521336521 is 125633125.

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 521336521 - 2³ = 521336513 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 521336521.

It is not an unprimeable number, because it can be changed into a prime (521336821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 961605 + ... + 962146.

It is an arithmetic number, because the mean of its divisors is an integer number (130815136).

Almost surely, 2^521336521 is an apocalyptic number.

It is an amenable number.

521336521 is a deficient number, since it is larger than the sum of its proper divisors (1924023).

521336521 is a wasteful number, since it uses less digits than its factorization.

521336521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1924022.

The product of its digits is 5400, while the sum is 28.

The square root of 521336521 is about 22832.7948573975. The cubic root of 521336521 is about 804.8335090275.

Adding to 521336521 its reverse (125633125), we get a palindrome (646969646).

The spelling of 521336521 in words is "five hundred twenty-one million, three hundred thirty-six thousand, five hundred twenty-one".