12518021 has 2 divisors, whose sum is σ = 12518022. Its totient is φ = 12518020.

The previous prime is 12517987. The next prime is 12518029. The reversal of 12518021 is 12081521.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12460900 + 57121 = 3530^2 + 239^2 .

It is a cyclic number.

It is not a de Polignac number, because 12518021 - 2¹⁸ = 12255877 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 12517984 and 12518002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12518029) 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 as a sum of consecutive naturals, namely, 6259010 + 6259011.

It is an arithmetic number, because the mean of its divisors is an integer number (6259011).

Almost surely, 2^12518021 is an apocalyptic number.

It is an amenable number.

12518021 is a deficient number, since it is larger than the sum of its proper divisors (1).

12518021 is an equidigital number, since it uses as much as digits as its factorization.

12518021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 160, while the sum is 20.

The square root of 12518021 is about 3538.0815423051. The cubic root of 12518021 is about 232.1909162241.

Adding to 12518021 its reverse (12081521), we get a palindrome (24599542).

The spelling of 12518021 in words is "twelve million, five hundred eighteen thousand, twenty-one".