516516661 has 4 divisors (see below), whose sum is σ = 546900012. Its totient is φ = 486133312.

The previous prime is 516516659. The next prime is 516516667. The reversal of 516516661 is 166615615.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 166615615 = 5 ⋅33323123.

It can be written as a sum of positive squares in 2 ways, for example, as 174081636 + 342435025 = 13194^2 + 18505^2 .

It is a cyclic number.

It is not a de Polignac number, because 516516661 - 2¹ = 516516659 is a prime.

It is a super-2 number, since 2×516516661² = 533578922181177842, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 516516661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (516516667) 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 3 ways as a sum of consecutive naturals, for example, 15191650 + ... + 15191683.

It is an arithmetic number, because the mean of its divisors is an integer number (136725003).

Almost surely, 2^516516661 is an apocalyptic number.

It is an amenable number.

516516661 is a deficient number, since it is larger than the sum of its proper divisors (30383351).

516516661 is a wasteful number, since it uses less digits than its factorization.

516516661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30383350.

The product of its digits is 32400, while the sum is 37.

The square root of 516516661 is about 22727.0029040347. The cubic root of 516516661 is about 802.3455439129.

The spelling of 516516661 in words is "five hundred sixteen million, five hundred sixteen thousand, six hundred sixty-one".