531643813 has 2 divisors, whose sum is σ = 531643814. Its totient is φ = 531643812.

The previous prime is 531643759. The next prime is 531643817. The reversal of 531643813 is 318346135.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 273141729 + 258502084 = 16527^2 + 16078^2 .

It is a cyclic number.

It is not a de Polignac number, because 531643813 - 2¹⁷ = 531512741 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (531643817) 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, 265821906 + 265821907.

It is an arithmetic number, because the mean of its divisors is an integer number (265821907).

Almost surely, 2^531643813 is an apocalyptic number.

It is an amenable number.

531643813 is a deficient number, since it is larger than the sum of its proper divisors (1).

531643813 is an equidigital number, since it uses as much as digits as its factorization.

531643813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25920, while the sum is 34.

The square root of 531643813 is about 23057.4025640357. The cubic root of 531643813 is about 810.1030265741.

Adding to 531643813 its reverse (318346135), we get a palindrome (849989948).

The spelling of 531643813 in words is "five hundred thirty-one million, six hundred forty-three thousand, eight hundred thirteen".