18065993 has 4 divisors (see below), whose sum is σ = 19708368. Its totient is φ = 16423620.

The previous prime is 18065981. The next prime is 18066007. The reversal of 18065993 is 39956081.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 39956081 = 11 ⋅3632371.

It is a cyclic number.

It is not a de Polignac number, because 18065993 - 2¹⁶ = 18000457 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18065993.

It is not an unprimeable number, because it can be changed into a prime (18065393) 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, 821171 + ... + 821192.

It is an arithmetic number, because the mean of its divisors is an integer number (4927092).

Almost surely, 2^18065993 is an apocalyptic number.

It is an amenable number.

18065993 is a deficient number, since it is larger than the sum of its proper divisors (1642375).

18065993 is a wasteful number, since it uses less digits than its factorization.

18065993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1642374.

The product of its (nonzero) digits is 58320, while the sum is 41.

The square root of 18065993 is about 4250.4109213110. The cubic root of 18065993 is about 262.3940276702.

The spelling of 18065993 in words is "eighteen million, sixty-five thousand, nine hundred ninety-three".