216835805 has 8 divisors (see below), whose sum is σ = 260534232. Its totient is φ = 173247808.

The previous prime is 216835777. The next prime is 216835811. The reversal of 216835805 is 508538612.

It can be written as a sum of positive squares in 4 ways, for example, as 24542116 + 192293689 = 4954^2 + 13867^2 .

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 216835805 - 2²² = 212641501 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 23222 + ... + 31191.

It is an arithmetic number, because the mean of its divisors is an integer number (32566779).

Almost surely, 2^216835805 is an apocalyptic number.

It is an amenable number.

216835805 is a deficient number, since it is larger than the sum of its proper divisors (43698427).

216835805 is an equidigital number, since it uses as much as digits as its factorization.

216835805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55215.

The product of its (nonzero) digits is 57600, while the sum is 38.

The square root of 216835805 is about 14725.3456665710. The cubic root of 216835805 is about 600.7728974735.

It can be divided in two parts, 2168 and 35805, that added together give a palindrome (37973).

The spelling of 216835805 in words is "two hundred sixteen million, eight hundred thirty-five thousand, eight hundred five".