218016809 has 8 divisors (see below), whose sum is σ = 226800000. Its totient is φ = 209318032.

The previous prime is 218016779. The next prime is 218016829. The reversal of 218016809 is 908610812.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 218016809 - 2¹² = 218012713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (218016829) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15809 + ... + 26190.

It is an arithmetic number, because the mean of its divisors is an integer number (28350000).

Almost surely, 2^218016809 is an apocalyptic number.

218016809 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

218016809 is a deficient number, since it is larger than the sum of its proper divisors (8783191).

218016809 is a wasteful number, since it uses less digits than its factorization.

218016809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42207.

The product of its (nonzero) digits is 6912, while the sum is 35.

The square root of 218016809 is about 14765.3922738273. The cubic root of 218016809 is about 601.8616336338.

The spelling of 218016809 in words is "two hundred eighteen million, sixteen thousand, eight hundred nine".