216826809 has 8 divisors (see below), whose sum is σ = 289201920. Its totient is φ = 144501456.

The previous prime is 216826777. The next prime is 216826837. The reversal of 216826809 is 908628612.

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

It is not a de Polignac number, because 216826809 - 2⁵ = 216826777 is a prime.

It is a super-2 number, since 2×216826809² = 94027730202244962, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (216826859) 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, 682 + ... + 20835.

It is an arithmetic number, because the mean of its divisors is an integer number (36150240).

Almost surely, 2^216826809 is an apocalyptic number.

It is an amenable number.

216826809 is a deficient number, since it is larger than the sum of its proper divisors (72375111).

216826809 is a wasteful number, since it uses less digits than its factorization.

216826809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24879.

The product of its (nonzero) digits is 82944, while the sum is 42.

The square root of 216826809 is about 14725.0402036803. The cubic root of 216826809 is about 600.7645891474.

The spelling of 216826809 in words is "two hundred sixteen million, eight hundred twenty-six thousand, eight hundred nine".