12718121 has 16 divisors (see below), whose sum is σ = 14242704. Its totient is φ = 11280384.

The previous prime is 12718093. The next prime is 12718157. The reversal of 12718121 is 12181721.

It can be written as a sum of positive squares in 8 ways, for example, as 44521 + 12673600 = 211^2 + 3560^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12718121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12718171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 65801 + ... + 65993.

It is an arithmetic number, because the mean of its divisors is an integer number (890169).

Almost surely, 2^12718121 is an apocalyptic number.

It is an amenable number.

12718121 is a deficient number, since it is larger than the sum of its proper divisors (1524583).

12718121 is a wasteful number, since it uses less digits than its factorization.

12718121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 380.

The product of its digits is 224, while the sum is 23.

The square root of 12718121 is about 3566.2474675771. The cubic root of 12718121 is about 233.4215691235.

Adding to 12718121 its reverse (12181721), we get a palindrome (24899842).

The spelling of 12718121 in words is "twelve million, seven hundred eighteen thousand, one hundred twenty-one".