521064788861 has 12 divisors (see below), whose sum is σ = 559737989460. Its totient is φ = 484903626240.

The previous prime is 521064788857. The next prime is 521064788891. The reversal of 521064788861 is 168887460125.

It can be written as a sum of positive squares in 6 ways, for example, as 42120100 + 521022668761 = 6490^2 + 721819^2 .

It is not a de Polignac number, because 521064788861 - 2² = 521064788857 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 521064788797 and 521064788806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521064788801) 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 11 ways as a sum of consecutive naturals, for example, 10103450 + ... + 10154891.

It is an arithmetic number, because the mean of its divisors is an integer number (46644832455).

Almost surely, 2^521064788861 is an apocalyptic number.

It is an amenable number.

521064788861 is a deficient number, since it is larger than the sum of its proper divisors (38673200599).

521064788861 is a wasteful number, since it uses less digits than its factorization.

521064788861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20258464 (or 20258447 counting only the distinct ones).

The product of its (nonzero) digits is 5160960, while the sum is 56.

The spelling of 521064788861 in words is "five hundred twenty-one billion, sixty-four million, seven hundred eighty-eight thousand, eight hundred sixty-one".