12215217 has 32 divisors (see below), whose sum is σ = 19456000. Its totient is φ = 6671808.

The previous prime is 12215201. The next prime is 12215219. The reversal of 12215217 is 71251221.

It is not a de Polignac number, because 12215217 - 2⁴ = 12215201 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Duffinian number.

It is a plaindrome in base 15.

It is a zygodrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 12215193 and 12215202.

It is not an unprimeable number, because it can be changed into a prime (12215219) 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 31 ways as a sum of consecutive naturals, for example, 61284 + ... + 61482.

It is an arithmetic number, because the mean of its divisors is an integer number (608000).

Almost surely, 2^12215217 is an apocalyptic number.

It is an amenable number.

12215217 is a deficient number, since it is larger than the sum of its proper divisors (7240783).

12215217 is a wasteful number, since it uses less digits than its factorization.

12215217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 325.

The product of its digits is 280, while the sum is 21.

The square root of 12215217 is about 3495.0274677032. The cubic root of 12215217 is about 230.3034243622.

Adding to 12215217 its reverse (71251221), we get a palindrome (83466438).

The spelling of 12215217 in words is "twelve million, two hundred fifteen thousand, two hundred seventeen".