516611561 has 4 divisors (see below), whose sum is σ = 518829012. Its totient is φ = 514394112.

The previous prime is 516611551. The next prime is 516611591. The reversal of 516611561 is 165116615.

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 152374336 + 364237225 = 12344^2 + 19085^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-516611561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (516611531) 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 3 ways as a sum of consecutive naturals, for example, 1108376 + ... + 1108841.

It is an arithmetic number, because the mean of its divisors is an integer number (129707253).

Almost surely, 2^516611561 is an apocalyptic number.

It is an amenable number.

516611561 is a deficient number, since it is larger than the sum of its proper divisors (2217451).

516611561 is a wasteful number, since it uses less digits than its factorization.

516611561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2217450.

The product of its digits is 5400, while the sum is 32.

The square root of 516611561 is about 22729.0906329312. The cubic root of 516611561 is about 802.3946794234.

The spelling of 516611561 in words is "five hundred sixteen million, six hundred eleven thousand, five hundred sixty-one".