531281 has 2 divisors, whose sum is σ = 531282. Its totient is φ = 531280.

The previous prime is 531263. The next prime is 531287. The reversal of 531281 is 182135.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 297025 + 234256 = 545^2 + 484^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-531281 is a prime.

It is a super-2 number, since 2×531281² = 564519001922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 531281.

It is not a weakly prime, because it can be changed into another prime (531287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 265640 + 265641.

It is an arithmetic number, because the mean of its divisors is an integer number (265641).

2⁵³¹²⁸¹ is an apocalyptic number.

It is an amenable number.

531281 is a deficient number, since it is larger than the sum of its proper divisors (1).

531281 is an equidigital number, since it uses as much as digits as its factorization.

531281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 240, while the sum is 20.

The square root of 531281 is about 728.8902523700. The cubic root of 531281 is about 80.9918703419.

The spelling of 531281 in words is "five hundred thirty-one thousand, two hundred eighty-one".