521541561 has 8 divisors (see below), whose sum is σ = 695494240. Its totient is φ = 347641632.

The previous prime is 521541557. The next prime is 521541569. The reversal of 521541561 is 165145125.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 521541561 - 2² = 521541557 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (521541569) 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 7 ways as a sum of consecutive naturals, for example, 32430 + ... + 45768.

It is an arithmetic number, because the mean of its divisors is an integer number (86936780).

Almost surely, 2^521541561 is an apocalyptic number.

It is an amenable number.

521541561 is a deficient number, since it is larger than the sum of its proper divisors (173952679).

521541561 is a wasteful number, since it uses less digits than its factorization.

521541561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26375.

The product of its digits is 6000, while the sum is 30.

The square root of 521541561 is about 22837.2844489007. The cubic root of 521541561 is about 804.9390080199.

Adding to 521541561 its reverse (165145125), we get a palindrome (686686686).

The spelling of 521541561 in words is "five hundred twenty-one million, five hundred forty-one thousand, five hundred sixty-one".