521871718687 has 8 divisors (see below), whose sum is σ = 577333118592. Its totient is φ = 467746738200.

The previous prime is 521871718679. The next prime is 521871718733. The reversal of 521871718687 is 786817178125.

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

It is a cyclic number.

It is not a de Polignac number, because 521871718687 - 2³ = 521871718679 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521871718607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 334104033 + ... + 334105594.

It is an arithmetic number, because the mean of its divisors is an integer number (72166639824).

Almost surely, 2^521871718687 is an apocalyptic number.

521871718687 is a deficient number, since it is larger than the sum of its proper divisors (55461399905).

521871718687 is a wasteful number, since it uses less digits than its factorization.

521871718687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 668209709.

The product of its digits is 10536960, while the sum is 61.

The spelling of 521871718687 in words is "five hundred twenty-one billion, eight hundred seventy-one million, seven hundred eighteen thousand, six hundred eighty-seven".