18399001 has 2 divisors, whose sum is σ = 18399002. Its totient is φ = 18399000.

The previous prime is 18398983. The next prime is 18399023. The reversal of 18399001 is 10099381.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13104400 + 5294601 = 3620^2 + 2301^2 .

It is a cyclic number.

It is not a de Polignac number, because 18399001 - 2⁹ = 18398489 is a prime.

It is not a weakly prime, because it can be changed into another prime (10399001) 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, 9199500 + 9199501.

It is an arithmetic number, because the mean of its divisors is an integer number (9199501).

Almost surely, 2^18399001 is an apocalyptic number.

It is an amenable number.

18399001 is a deficient number, since it is larger than the sum of its proper divisors (1).

18399001 is an equidigital number, since it uses as much as digits as its factorization.

18399001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1944, while the sum is 31.

The square root of 18399001 is about 4289.4056697869. The cubic root of 18399001 is about 263.9964464245.

The spelling of 18399001 in words is "eighteen million, three hundred ninety-nine thousand, one".