18002001 has 8 divisors (see below), whose sum is σ = 24227424. Its totient is φ = 11888960.

The previous prime is 18001999. The next prime is 18002003. The reversal of 18002001 is 10020081.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18001999) and next prime (18002003).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18002001 - 2¹ = 18001999 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18002003) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27720 + ... + 28361.

It is an arithmetic number, because the mean of its divisors is an integer number (3028428).

Almost surely, 2^18002001 is an apocalyptic number.

It is an amenable number.

18002001 is a deficient number, since it is larger than the sum of its proper divisors (6225423).

18002001 is a wasteful number, since it uses less digits than its factorization.

18002001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56191.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 18002001 is about 4242.8765006773. The cubic root of 18002001 is about 262.0838503639.

Adding to 18002001 its reverse (10020081), we get a palindrome (28022082).

The spelling of 18002001 in words is "eighteen million, two thousand, one".