12215205 has 20 divisors (see below), whose sum is σ = 21897612. Its totient is φ = 6514560.

The previous prime is 12215201. The next prime is 12215219. The reversal of 12215205 is 50251221.

12215205 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 7193124 + 5022081 = 2682^2 + 2241^2 .

It is not a de Polignac number, because 12215205 - 2² = 12215201 is a prime.

It is a super-2 number, since 2×12215205² = 298422466384050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12215201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 14676 + ... + 15485.

Almost surely, 2^12215205 is an apocalyptic number.

12215205 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

12215205 is a deficient number, since it is larger than the sum of its proper divisors (9682407).

12215205 is an equidigital number, since it uses as much as digits as its factorization.

12215205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30178 (or 30169 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 12215205 is about 3495.0257509781. The cubic root of 12215205 is about 230.3033489470.

Adding to 12215205 its reverse (50251221), we get a palindrome (62466426).

The spelling of 12215205 in words is "twelve million, two hundred fifteen thousand, two hundred five".