Positive, nonzero integers within three units
Scientific notation expresses a quantity as the product of its significand with 10 raised to an integer exponent.
A number multiplied with its reciprocal is one.
The reciprocal of 19.
A numerical palindrome has the same value when all of its digits are reversed.
The number 19 is not a palindrome.
A Prime Number
A prime number is a positive integer that is divisible only by itself and one.
Nineteen is the 8th prime number. See primes in Base 10 Decimal
Not A Composite
Composites have more than just these two factors.
Nineteen is not a composite number because it has exactly two factors: One and Nineteen
The number nineteen has the following 1 prime factor:
The prime factorization of a positive integer is the unique list of prime factors together with their multiplicities
The number nineteen in 35 different bases