18919073 has 4 divisors (see below), whose sum is σ = 18955908. Its totient is φ = 18882240.

The previous prime is 18919067. The next prime is 18919091. The reversal of 18919073 is 37091981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 37091981 = 2083 ⋅17807.

It can be written as a sum of positive squares in 2 ways, for example, as 3810304 + 15108769 = 1952^2 + 3887^2 .

It is a cyclic number.

It is not a de Polignac number, because 18919073 - 2⁴ = 18919057 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 (18919013) 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, 17636 + ... + 18677.

It is an arithmetic number, because the mean of its divisors is an integer number (4738977).

Almost surely, 2^18919073 is an apocalyptic number.

It is an amenable number.

18919073 is a deficient number, since it is larger than the sum of its proper divisors (36835).

18919073 is an equidigital number, since it uses as much as digits as its factorization.

18919073 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36834.

The product of its (nonzero) digits is 13608, while the sum is 38.

The square root of 18919073 is about 4349.6060741175. The cubic root of 18919073 is about 266.4607735363.

The spelling of 18919073 in words is "eighteen million, nine hundred nineteen thousand, seventy-three".