516556561561 has 8 divisors (see below), whose sum is σ = 518939964680. Its totient is φ = 514174269312.

The previous prime is 516556561487. The next prime is 516556561673. The reversal of 516556561561 is 165165655615.

It can be written as a sum of positive squares in 4 ways, for example, as 49131382336 + 467425179225 = 221656^2 + 683685^2 .

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 516556561561 - 2¹³ = 516556553369 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 516556561499 and 516556561508.

It is not an unprimeable number, because it can be changed into a prime (516556261561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 661741 + ... + 1212853.

It is an arithmetic number, because the mean of its divisors is an integer number (64867495585).

Almost surely, 2^516556561561 is an apocalyptic number.

It is an amenable number.

516556561561 is a deficient number, since it is larger than the sum of its proper divisors (2383403119).

516556561561 is a wasteful number, since it uses less digits than its factorization.

516556561561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 555435.

The product of its digits is 4050000, while the sum is 52.

The spelling of 516556561561 in words is "five hundred sixteen billion, five hundred fifty-six million, five hundred sixty-one thousand, five hundred sixty-one".