216448985 has 4 divisors (see below), whose sum is σ = 259738788. Its totient is φ = 173159184.

The previous prime is 216448957. The next prime is 216448997. The reversal of 216448985 is 589844612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 50013184 + 166435801 = 7072^2 + 12901^2 .

It is a cyclic number.

It is not a de Polignac number, because 216448985 - 2¹² = 216444889 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 21644894 + ... + 21644903.

It is an arithmetic number, because the mean of its divisors is an integer number (64934697).

Almost surely, 2^216448985 is an apocalyptic number.

It is an amenable number.

216448985 is a deficient number, since it is larger than the sum of its proper divisors (43289803).

216448985 is an equidigital number, since it uses as much as digits as its factorization.

216448985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43289802.

The product of its digits is 552960, while the sum is 47.

The square root of 216448985 is about 14712.2053071591. The cubic root of 216448985 is about 600.4154391360.

The spelling of 216448985 in words is "two hundred sixteen million, four hundred forty-eight thousand, nine hundred eighty-five".