18001213 has 2 divisors, whose sum is σ = 18001214. Its totient is φ = 18001212.

The previous prime is 18001201. The next prime is 18001237. The reversal of 18001213 is 31210081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10936249 + 7064964 = 3307^2 + 2658^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18001213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18001253) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9000606 + 9000607.

It is an arithmetic number, because the mean of its divisors is an integer number (9000607).

Almost surely, 2^18001213 is an apocalyptic number.

It is an amenable number.

18001213 is a deficient number, since it is larger than the sum of its proper divisors (1).

18001213 is an equidigital number, since it uses as much as digits as its factorization.

18001213 is an odious number, because the sum of its binary digits is odd.

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

The square root of 18001213 is about 4242.7836381319. The cubic root of 18001213 is about 262.0800262503.

Adding to 18001213 its reverse (31210081), we get a palindrome (49211294).

The spelling of 18001213 in words is "eighteen million, one thousand, two hundred thirteen".