12217855 has 24 divisors (see below), whose sum is σ = 16733520. Its totient is φ = 8536320.

The previous prime is 12217811. The next prime is 12217859. The reversal of 12217855 is 55871221.

It is not a de Polignac number, because 12217855 - 2¹¹ = 12215807 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12217859) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15675 + ... + 16435.

It is an arithmetic number, because the mean of its divisors is an integer number (697230).

Almost surely, 2^12217855 is an apocalyptic number.

12217855 is a deficient number, since it is larger than the sum of its proper divisors (4515665).

12217855 is a wasteful number, since it uses less digits than its factorization.

12217855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 811 (or 798 counting only the distinct ones).

The product of its digits is 5600, while the sum is 31.

The square root of 12217855 is about 3495.4048406444. The cubic root of 12217855 is about 230.3200019557.

The spelling of 12217855 in words is "twelve million, two hundred seventeen thousand, eight hundred fifty-five".