12218445 has 20 divisors (see below), whose sum is σ = 21903420. Its totient is φ = 6516288.

The previous prime is 12218443. The next prime is 12218489. The reversal of 12218445 is 54481221.

12218445 is a `hidden beast` number, since 1 + 2 + 218 + 445 = 666.

12218445 is digitally balanced in base 2 and base 4, because in such bases 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 5731236 + 6487209 = 2394^2 + 2547^2 .

It is not a de Polignac number, because 12218445 - 2¹ = 12218443 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12218443) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 14680 + ... + 15489.

It is an arithmetic number, because the mean of its divisors is an integer number (1095171).

Almost surely, 2^12218445 is an apocalyptic number.

12218445 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

12218445 is a deficient number, since it is larger than the sum of its proper divisors (9684975).

12218445 is an equidigital number, since it uses as much as digits as its factorization.

12218445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30186 (or 30177 counting only the distinct ones).

The product of its digits is 2560, while the sum is 27.

The square root of 12218445 is about 3495.4892361442. The cubic root of 12218445 is about 230.3237092789.

Adding to 12218445 its reverse (54481221), we get a palindrome (66699666).

The spelling of 12218445 in words is "twelve million, two hundred eighteen thousand, four hundred forty-five".