12221665 has 8 divisors (see below), whose sum is σ = 14760360. Its totient is φ = 9714432.

The previous prime is 12221611. The next prime is 12221669. The reversal of 12221665 is 56612221.

It can be written as a sum of positive squares in 4 ways, for example, as 277729 + 11943936 = 527^2 + 3456^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12221665 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12221669) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7000 + ... + 8569.

It is an arithmetic number, because the mean of its divisors is an integer number (1845045).

Almost surely, 2^12221665 is an apocalyptic number.

It is an amenable number.

12221665 is a deficient number, since it is larger than the sum of its proper divisors (2538695).

12221665 is a wasteful number, since it uses less digits than its factorization.

12221665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15731.

The product of its digits is 1440, while the sum is 25.

The square root of 12221665 is about 3495.9497994107. The cubic root of 12221665 is about 230.3439403641.

Adding to 12221665 its reverse (56612221), we get a palindrome (68833886).

The spelling of 12221665 in words is "twelve million, two hundred twenty-one thousand, six hundred sixty-five".