216530449 has 2 divisors, whose sum is σ = 216530450. Its totient is φ = 216530448.

The previous prime is 216530359. The next prime is 216530453. The reversal of 216530449 is 944035612.

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., 148352400 + 68178049 = 12180^2 + 8257^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216530449 is a prime.

It is not a weakly prime, because it can be changed into another prime (216530459) 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, 108265224 + 108265225.

It is an arithmetic number, because the mean of its divisors is an integer number (108265225).

Almost surely, 2^216530449 is an apocalyptic number.

It is an amenable number.

216530449 is a deficient number, since it is larger than the sum of its proper divisors (1).

216530449 is an equidigital number, since it uses as much as digits as its factorization.

216530449 is an odious number, because the sum of its binary digits is odd.

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

The square root of 216530449 is about 14714.9736323243. The cubic root of 216530449 is about 600.4907549713.

The spelling of 216530449 in words is "two hundred sixteen million, five hundred thirty thousand, four hundred forty-nine".