# 161

## 161 is an odd composite number composed of two prime numbers multiplied together.

What does the number 161 look like?

This visualization shows the relationship between its 2 prime factors (large circles) and 4 divisors.

161 is an odd composite number. It is composed of two distinct prime numbers multiplied together. It has a total of four divisors.

## Prime factorization of 161:

### 7 × 23

See below for interesting mathematical facts about the number 161 from the Numbermatics database.

### Names of 161

• Cardinal: 161 can be written as One hundred sixty-one.

### Scientific notation

• Scientific notation: 1.61 × 102

### Factors of 161

• Number of distinct prime factors ω(n): 2
• Total number of prime factors Ω(n): 2
• Sum of prime factors: 30

### Divisors of 161

• Number of divisors d(n): 4
• Complete list of divisors:
• Sum of all divisors σ(n): 192
• Sum of proper divisors (its aliquot sum) s(n): 31
• 161 is a deficient number, because the sum of its proper divisors (31) is less than itself. Its deficiency is 130

### Bases of 161

• Binary: 101000012
• Base-36: 4H

### Squares and roots of 161

• 161 squared (1612) is 25921
• 161 cubed (1613) is 4173281
• The square root of 161 is 12.6885775405
• The cube root of 161 is 5.4401218253

### Scales and comparisons

How big is 161?
• 161 seconds is equal to 2 minutes, 41 seconds.
• To count from 1 to 161 would take you about twenty seconds.

This is a very rough estimate, based on a speaking rate of half a second every third order of magnitude. If you speak quickly, you could probably say any randomly-chosen number between one and a thousand in around half a second. Very big numbers obviously take longer to say, so we add half a second for every extra x1000. (We do not count involuntary pauses, bathroom breaks or the necessity of sleep in our calculation!)

• A cube with a volume of 161 cubic inches would be around 0.5 feet tall.

### Recreational maths with 161

• 161 is the same when its digits are reversed! That makes it a palindromic number.
• The number of decimal digits it has is: 3
• The sum of 161's digits is 8
• More coming soon!