18009641 has 8 divisors (see below), whose sum is σ = 19428360. Its totient is φ = 16595712.

The previous prime is 18009637. The next prime is 18009659. The reversal of 18009641 is 14690081.

It can be written as a sum of positive squares in 4 ways, for example, as 3225616 + 14784025 = 1796^2 + 3845^2 .

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 18009641 - 2² = 18009637 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18009631) 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 in 7 ways as a sum of consecutive naturals, for example, 12431 + ... + 13803.

It is an arithmetic number, because the mean of its divisors is an integer number (2428545).

Almost surely, 2^18009641 is an apocalyptic number.

It is an amenable number.

18009641 is a deficient number, since it is larger than the sum of its proper divisors (1418719).

18009641 is a wasteful number, since it uses less digits than its factorization.

18009641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2395.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 18009641 is about 4243.7767377655. The cubic root of 18009641 is about 262.1209210100.

The spelling of 18009641 in words is "eighteen million, nine thousand, six hundred forty-one".