18009401 has 2 divisors, whose sum is σ = 18009402. Its totient is φ = 18009400.

The previous prime is 18009323. The next prime is 18009403. The reversal of 18009401 is 10490081.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13868176 + 4141225 = 3724^2 + 2035^2 .

It is a cyclic number.

It is not a de Polignac number, because 18009401 - 2¹⁰ = 18008377 is a prime.

It is a Sophie Germain prime.

Together with 18009403, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (18009403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9004700 + 9004701.

It is an arithmetic number, because the mean of its divisors is an integer number (9004701).

Almost surely, 2^18009401 is an apocalyptic number.

It is an amenable number.

18009401 is a deficient number, since it is larger than the sum of its proper divisors (1).

18009401 is an equidigital number, since it uses as much as digits as its factorization.

18009401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 18009401 is about 4243.7484609717. The cubic root of 18009401 is about 262.1197566466.

Adding to 18009401 its reverse (10490081), we get a palindrome (28499482).

The spelling of 18009401 in words is "eighteen million, nine thousand, four hundred one".