518561 has 4 divisors (see below), whose sum is σ = 527124. Its totient is φ = 510000.

The previous prime is 518543. The next prime is 518579. The reversal of 518561 is 165815.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (518543) and next prime (518579).

It can be written as a sum of positive squares in 2 ways, for example, as 28561 + 490000 = 169^2 + 700^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-518561 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 518561.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 518561.

It is not an unprimeable number, because it can be changed into a prime (518521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4190 + ... + 4311.

It is an arithmetic number, because the mean of its divisors is an integer number (131781).

2⁵¹⁸⁵⁶¹ is an apocalyptic number.

It is an amenable number.

518561 is a deficient number, since it is larger than the sum of its proper divisors (8563).

518561 is an equidigital number, since it uses as much as digits as its factorization.

518561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8562.

The product of its digits is 1200, while the sum is 26.

The square root of 518561 is about 720.1117968760. Note that the first 3 decimals coincide. The cubic root of 518561 is about 80.3402694072.

The spelling of 518561 in words is "five hundred eighteen thousand, five hundred sixty-one".