216530537 has 2 divisors, whose sum is σ = 216530538. Its totient is φ = 216530536.

The previous prime is 216530459. The next prime is 216530569. The reversal of 216530537 is 735035612.

It is an a-pointer prime, because the next prime (216530569) can be obtained adding 216530537 to its sum of digits (32).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 200817241 + 15713296 = 14171^2 + 3964^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216530537 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (216530737) 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, 108265268 + 108265269.

It is an arithmetic number, because the mean of its divisors is an integer number (108265269).

Almost surely, 2^216530537 is an apocalyptic number.

It is an amenable number.

216530537 is a deficient number, since it is larger than the sum of its proper divisors (1).

216530537 is an equidigital number, since it uses as much as digits as its factorization.

216530537 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18900, while the sum is 32.

The square root of 216530537 is about 14714.9766224755. The cubic root of 216530537 is about 600.4908363196.

The spelling of 216530537 in words is "two hundred sixteen million, five hundred thirty thousand, five hundred thirty-seven".