12121216 has 32 divisors (see below), whose sum is σ = 24305580. Its totient is φ = 6021120.

The previous prime is 12121211. The next prime is 12121231. The reversal of 12121216 is 61212121.

It can be written as a sum of positive squares in 2 ways, for example, as 12110400 + 10816 = 3480^2 + 104^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is an alternating number because its digits alternate between odd and even.

It is a self number, because there is not a number n which added to its sum of digits gives 12121216.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12121211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35800 + ... + 36136.

Almost surely, 2^12121216 is an apocalyptic number.

12121216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

12121216 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

12121216 is an equidigital number, since it uses as much as digits as its factorization.

12121216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 632 (or 620 counting only the distinct ones).

The product of its digits is 48, while the sum is 16.

The square root of 12121216 is about 3481.5536761624. The cubic root of 12121216 is about 229.7111433634.

Adding to 12121216 its reverse (61212121), we get a palindrome (73333337).

The spelling of 12121216 in words is "twelve million, one hundred twenty-one thousand, two hundred sixteen".