18004121 has 2 divisors, whose sum is σ = 18004122. Its totient is φ = 18004120.

The previous prime is 18004081. The next prime is 18004171. The reversal of 18004121 is 12140081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11055625 + 6948496 = 3325^2 + 2636^2 .

It is an emirp because it is prime and its reverse (12140081) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18004121 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18004121.

It is not a weakly prime, because it can be changed into another prime (18004171) 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, 9002060 + 9002061.

It is an arithmetic number, because the mean of its divisors is an integer number (9002061).

Almost surely, 2^18004121 is an apocalyptic number.

It is an amenable number.

18004121 is a deficient number, since it is larger than the sum of its proper divisors (1).

18004121 is an equidigital number, since it uses as much as digits as its factorization.

18004121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 17.

The square root of 18004121 is about 4243.1263238325. The cubic root of 18004121 is about 262.0941380342.

The spelling of 18004121 in words is "eighteen million, four thousand, one hundred twenty-one".