12216401 has 8 divisors (see below), whose sum is σ = 12854184. Its totient is φ = 11594880.

The previous prime is 12216397. The next prime is 12216403. The reversal of 12216401 is 10461221.

It can be written as a sum of positive squares in 4 ways, for example, as 2637376 + 9579025 = 1624^2 + 3095^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 12216401 - 2² = 12216397 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12216401.

It is not an unprimeable number, because it can be changed into a prime (12216403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2510 + ... + 5543.

It is an arithmetic number, because the mean of its divisors is an integer number (1606773).

Almost surely, 2^12216401 is an apocalyptic number.

It is an amenable number.

12216401 is a deficient number, since it is larger than the sum of its proper divisors (637783).

12216401 is an equidigital number, since it uses as much as digits as its factorization.

12216401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8131.

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 12216401 is about 3495.1968471032. The cubic root of 12216401 is about 230.3108650936.

Adding to 12216401 its reverse (10461221), we get a palindrome (22677622).

The spelling of 12216401 in words is "twelve million, two hundred sixteen thousand, four hundred one".