158 (number)
From Halbeeg, the open encyclopedia · Af-Soomaali
49 languages
158 is a natural number falling between 157 and 159. It is among the common numbers used in counting and measurement, and is written in the decimal system as three digits: 1 in the hundreds place, 5 in the tens place, and 8 in the units place.
158 is an even number, because it can be divided by 2 without remainder. It is also a composite number, meaning it has divisors other than 1 and itself.
Mathematical properties
The prime factorization of 158 is 2 × 79. Both 2 and 79 are prime numbers, so 158 is classified as a semiprime—a number that is the product of exactly two prime numbers. Its divisors are 1, 2, 79, and 158.
The sum of its proper divisors (those less than itself) is 1 + 2 + 79 = 82. For this reason, 158 is a deficient number, because this sum is less than the number itself.
Representation in other systems
In Roman numerals, 158 is written as CLVIII. In binary it is 10011110, and in hexadecimal it is 9E. The sum of its decimal digits is 1 + 5 + 8 = 14.
General use
Like other three-digit numbers, 158 appears in street addresses, postal codes, year numbering (such as the year 158 CE), and standard measurements like 158 centimetres. Such uses have no particular mathematical significance; they are simply numerical labels.