216804449 has 2 divisors, whose sum is σ = 216804450. Its totient is φ = 216804448.

The previous prime is 216804443. The next prime is 216804461. The reversal of 216804449 is 944408612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 203262049 + 13542400 = 14257^2 + 3680^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216804449 is a prime.

It is not a weakly prime, because it can be changed into another prime (216804443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108402224 + 108402225.

It is an arithmetic number, because the mean of its divisors is an integer number (108402225).

Almost surely, 2^216804449 is an apocalyptic number.

It is an amenable number.

216804449 is a deficient number, since it is larger than the sum of its proper divisors (1).

216804449 is an equidigital number, since it uses as much as digits as its factorization.

216804449 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 55296, while the sum is 38.

The square root of 216804449 is about 14724.2809332069. The cubic root of 216804449 is about 600.7439373992.

The spelling of 216804449 in words is "two hundred sixteen million, eight hundred four thousand, four hundred forty-nine".