531815213 has 2 divisors, whose sum is σ = 531815214. Its totient is φ = 531815212.

The previous prime is 531815209. The next prime is 531815239. The reversal of 531815213 is 312518135.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 439405444 + 92409769 = 20962^2 + 9613^2 .

It is a cyclic number.

It is not a de Polignac number, because 531815213 - 2² = 531815209 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (531815413) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 265907606 + 265907607.

It is an arithmetic number, because the mean of its divisors is an integer number (265907607).

Almost surely, 2^531815213 is an apocalyptic number.

It is an amenable number.

531815213 is a deficient number, since it is larger than the sum of its proper divisors (1).

531815213 is an equidigital number, since it uses as much as digits as its factorization.

531815213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3600, while the sum is 29.

The square root of 531815213 is about 23061.1190751880. The cubic root of 531815213 is about 810.1900752937.

The spelling of 531815213 in words is "five hundred thirty-one million, eight hundred fifteen thousand, two hundred thirteen".