218215105 has 8 divisors (see below), whose sum is σ = 262303272. Its totient is φ = 174275328.

The previous prime is 218215103. The next prime is 218215121. The reversal of 218215105 is 501512812.

It can be written as a sum of positive squares in 4 ways, for example, as 49449024 + 168766081 = 7032^2 + 12991^2 .

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 218215105 - 2¹ = 218215103 is a prime.

It is a super-2 number, since 2×218215105² = 95235664100322050, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 218215105.

It is not an unprimeable number, because it can be changed into a prime (218215103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33834 + ... + 39763.

It is an arithmetic number, because the mean of its divisors is an integer number (32787909).

Almost surely, 2^218215105 is an apocalyptic number.

It is an amenable number.

218215105 is a deficient number, since it is larger than the sum of its proper divisors (44088167).

218215105 is an equidigital number, since it uses as much as digits as its factorization.

218215105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74195.

The product of its (nonzero) digits is 800, while the sum is 25.

The square root of 218215105 is about 14772.1056386691. The cubic root of 218215105 is about 602.0440516618.

Adding to 218215105 its reverse (501512812), we get a palindrome (719727917).

The spelling of 218215105 in words is "two hundred eighteen million, two hundred fifteen thousand, one hundred five".