18001601 has 2 divisors, whose sum is σ = 18001602. Its totient is φ = 18001600.

The previous prime is 18001597. The next prime is 18001631. The reversal of 18001601 is 10610081.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16192576 + 1809025 = 4024^2 + 1345^2 .

It is an emirp because it is prime and its reverse (10610081) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18001601 - 2² = 18001597 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 18001601.

It is not a weakly prime, because it can be changed into another prime (18001631) 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, 9000800 + 9000801.

It is an arithmetic number, because the mean of its divisors is an integer number (9000801).

Almost surely, 2^18001601 is an apocalyptic number.

It is an amenable number.

18001601 is a deficient number, since it is larger than the sum of its proper divisors (1).

18001601 is an equidigital number, since it uses as much as digits as its factorization.

18001601 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 17.

The square root of 18001601 is about 4242.8293625834. The cubic root of 18001601 is about 262.0819092034.

Adding to 18001601 its reverse (10610081), we get a palindrome (28611682).

The spelling of 18001601 in words is "eighteen million, one thousand, six hundred one".