18043601 has 4 divisors (see below), whose sum is σ = 18055092. Its totient is φ = 18032112.

The previous prime is 18043591. The next prime is 18043603. The reversal of 18043601 is 10634081.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 10634081 = 157 ⋅67733.

It can be written as a sum of positive squares in 2 ways, for example, as 15808576 + 2235025 = 3976^2 + 1495^2 .

It is a cyclic number.

It is not a de Polignac number, because 18043601 - 2⁶ = 18043537 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18043603) 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 3 ways as a sum of consecutive naturals, for example, 2930 + ... + 6683.

It is an arithmetic number, because the mean of its divisors is an integer number (4513773).

Almost surely, 2^18043601 is an apocalyptic number.

It is an amenable number.

18043601 is a deficient number, since it is larger than the sum of its proper divisors (11491).

18043601 is an equidigital number, since it uses as much as digits as its factorization.

18043601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11490.

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 18043601 is about 4247.7760063356. The cubic root of 18043601 is about 262.2855742494.

Adding to 18043601 its reverse (10634081), we get a palindrome (28677682).

The spelling of 18043601 in words is "eighteen million, forty-three thousand, six hundred one".