521659541 has 4 divisors (see below), whose sum is σ = 561787212. Its totient is φ = 481531872.

The previous prime is 521659499. The next prime is 521659571. The reversal of 521659541 is 145956125.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 283080625 + 238578916 = 16825^2 + 15446^2 .

It is a cyclic number.

It is not a de Polignac number, because 521659541 - 2⁶ = 521659477 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 521659495 and 521659504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521659571) 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, 20063816 + ... + 20063841.

It is an arithmetic number, because the mean of its divisors is an integer number (140446803).

Almost surely, 2^521659541 is an apocalyptic number.

It is an amenable number.

521659541 is a deficient number, since it is larger than the sum of its proper divisors (40127671).

521659541 is a wasteful number, since it uses less digits than its factorization.

521659541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40127670.

The product of its digits is 54000, while the sum is 38.

The square root of 521659541 is about 22839.8673595098. The cubic root of 521659541 is about 804.9996996000. Note that the first 3 decimals are identical.

The spelling of 521659541 in words is "five hundred twenty-one million, six hundred fifty-nine thousand, five hundred forty-one".