216469309 has 18 divisors (see below), whose sum is σ = 255615930. Its totient is φ = 182782656.

The previous prime is 216469283. The next prime is 216469321. The reversal of 216469309 is 903964612.

It can be written as a sum of positive squares in 3 ways, for example, as 49491225 + 166978084 = 7035^2 + 12922^2 .

It is not a de Polignac number, because 216469309 - 2⁹ = 216468797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216461309) 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 in 17 ways as a sum of consecutive naturals, for example, 260707 + ... + 261535.

It is an arithmetic number, because the mean of its divisors is an integer number (14200885).

Almost surely, 2^216469309 is an apocalyptic number.

It is an amenable number.

216469309 is a deficient number, since it is larger than the sum of its proper divisors (39146621).

216469309 is an frugal number, since it uses more digits than its factorization.

216469309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 989 (or 909 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 40.

The square root of 216469309 is about 14712.8960099635. The cubic root of 216469309 is about 600.4342310336.

The spelling of 216469309 in words is "two hundred sixteen million, four hundred sixty-nine thousand, three hundred nine".