216840055 has 8 divisors (see below), whose sum is σ = 264474144. Its totient is φ = 170628000.

The previous prime is 216840023. The next prime is 216840061. The reversal of 216840055 is 550048612.

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

It is not a de Polignac number, because 216840055 - 2⁵ = 216840023 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 216839999 and 216840026.

It is a congruent 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 7 ways as a sum of consecutive naturals, for example, 355171 + ... + 355780.

It is an arithmetic number, because the mean of its divisors is an integer number (33059268).

Almost surely, 2^216840055 is an apocalyptic number.

216840055 is a deficient number, since it is larger than the sum of its proper divisors (47634089).

216840055 is an equidigital number, since it uses as much as digits as its factorization.

216840055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 711017.

The product of its (nonzero) digits is 9600, while the sum is 31.

The square root of 216840055 is about 14725.4899748701. The cubic root of 216840055 is about 600.7768225143.

Adding to 216840055 its reverse (550048612), we get a palindrome (766888667).

The spelling of 216840055 in words is "two hundred sixteen million, eight hundred forty thousand, fifty-five".