518981 has 2 divisors, whose sum is σ = 518982. Its totient is φ = 518980.

The previous prime is 518953. The next prime is 518983. The reversal of 518981 is 189815.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 330625 + 188356 = 575^2 + 434^2 .

It is a cyclic number.

It is not a de Polignac number, because 518981 - 2¹⁴ = 502597 is a prime.

It is a super-2 number, since 2×518981² = 538682556722, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 518983, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (518983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 259490 + 259491.

It is an arithmetic number, because the mean of its divisors is an integer number (259491).

2⁵¹⁸⁹⁸¹ is an apocalyptic number.

It is an amenable number.

518981 is a deficient number, since it is larger than the sum of its proper divisors (1).

518981 is an equidigital number, since it uses as much as digits as its factorization.

518981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2880, while the sum is 32.

The square root of 518981 is about 720.4033592370. The cubic root of 518981 is about 80.3619536497.

The spelling of 518981 in words is "five hundred eighteen thousand, nine hundred eighty-one".