516781665 has 48 divisors (see below), whose sum is σ = 956292480. Its totient is φ = 257402880.

The previous prime is 516781637. The next prime is 516781679. The reversal of 516781665 is 566187615.

516781665 is a `hidden beast` number, since 516 + 78 + 1 + 6 + 65 = 666.

It is not a de Polignac number, because 516781665 - 2¹⁶ = 516716129 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 516781665.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 56449 + ... + 64961.

It is an arithmetic number, because the mean of its divisors is an integer number (19922760).

Almost surely, 2^516781665 is an apocalyptic number.

It is an amenable number.

516781665 is a deficient number, since it is larger than the sum of its proper divisors (439510815).

516781665 is a wasteful number, since it uses less digits than its factorization.

516781665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8614 (or 8611 counting only the distinct ones).

The product of its digits is 302400, while the sum is 45.

The square root of 516781665 is about 22732.8323136384. The cubic root of 516781665 is about 802.4827375679.

The spelling of 516781665 in words is "five hundred sixteen million, seven hundred eighty-one thousand, six hundred sixty-five".