517381 has 2 divisors, whose sum is σ = 517382. Its totient is φ = 517380.

The previous prime is 517373. The next prime is 517393. The reversal of 517381 is 183715.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 349281 + 168100 = 591^2 + 410^2 .

It is a cyclic number.

It is not a de Polignac number, because 517381 - 2³ = 517373 is a prime.

It is a super-2 number, since 2×517381² = 535366198322, which contains 22 as substring.

517381 is a lucky number.

It is equal to p₄₂₈₅₆ and since 517381 and 42856 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (517081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 258690 + 258691.

It is an arithmetic number, because the mean of its divisors is an integer number (258691).

2⁵¹⁷³⁸¹ is an apocalyptic number.

It is an amenable number.

517381 is a deficient number, since it is larger than the sum of its proper divisors (1).

517381 is an equidigital number, since it uses as much as digits as its factorization.

517381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 840, while the sum is 25.

The square root of 517381 is about 719.2920130239. The cubic root of 517381 is about 80.2792842857.

It can be divided in two parts, 517 and 381, that added together give a palindrome (898).

The spelling of 517381 in words is "five hundred seventeen thousand, three hundred eighty-one".