18845993 has 4 divisors (see below), whose sum is σ = 19665408. Its totient is φ = 18026580.

The previous prime is 18845977. The next prime is 18846001. The reversal of 18845993 is 39954881.

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.

It is a cyclic number.

It is not a de Polignac number, because 18845993 - 2⁴ = 18845977 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 (18845963) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 409673 + ... + 409718.

It is an arithmetic number, because the mean of its divisors is an integer number (4916352).

Almost surely, 2^18845993 is an apocalyptic number.

It is an amenable number.

18845993 is a deficient number, since it is larger than the sum of its proper divisors (819415).

18845993 is an equidigital number, since it uses as much as digits as its factorization.

18845993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 819414.

The product of its digits is 311040, while the sum is 47.

The square root of 18845993 is about 4341.1971851092. The cubic root of 18845993 is about 266.1172387262.

The spelling of 18845993 in words is "eighteen million, eight hundred forty-five thousand, nine hundred ninety-three".