531509873 has 2 divisors, whose sum is σ = 531509874. Its totient is φ = 531509872.

The previous prime is 531509827. The next prime is 531509893. The reversal of 531509873 is 378905135.

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., 492484864 + 39025009 = 22192^2 + 6247^2 .

It is a cyclic number.

It is not a de Polignac number, because 531509873 - 2¹⁰ = 531508849 is a prime.

It is a super-2 number, since 2×531509873² = 565005490192952258, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is equal to p_27925763 and since 531509873 and 27925763 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 531509873.

It is not a weakly prime, because it can be changed into another prime (531509813) by changing a digit.

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 as a sum of consecutive naturals, namely, 265754936 + 265754937.

It is an arithmetic number, because the mean of its divisors is an integer number (265754937).

Almost surely, 2^531509873 is an apocalyptic number.

It is an amenable number.

531509873 is a deficient number, since it is larger than the sum of its proper divisors (1).

531509873 is an equidigital number, since it uses as much as digits as its factorization.

531509873 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 113400, while the sum is 41.

The square root of 531509873 is about 23054.4978908672. The cubic root of 531509873 is about 810.0349895976.

The spelling of 531509873 in words is "five hundred thirty-one million, five hundred nine thousand, eight hundred seventy-three".