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Number Problems
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Number Problems
Prime, palindrome, Armstrong and digit problems. 42 problems · Beginner level.
All
Easy
Medium
Hard
42 problems
Special numbers
✓
Armstrong Number
easy
✓
Palindrome Number
easy
✓
Strong Number
easy
✓
Automorphic Number
easy
✓
Neon Number
easy
✓
Harshad (Niven) Number
easy
✓
Spy Number
easy
✓
Perfect Square
easy
✓
Prime Number
easy
✓
Perfect Number
medium
✓
Happy Number
medium
✓
Disarium Number
medium
✓
Twin Prime Check
medium
✓
Emirp Number
medium
Factors and divisibility
✓
Factors of a Number
easy
✓
GCD of Two Numbers
easy
✓
Count the Divisors
easy
✓
Prime Factorization
medium
✓
LCM of Two Numbers
medium
✓
Divisible by 3 and 5
beginner
Conversions
✓
Decimal to Binary
easy
✓
Binary to Decimal
easy
✓
Decimal to Octal and Hexadecimal
medium
✓
Integer to Roman Numeral
medium
✓
Roman Numeral to Integer
medium
✓
Currency Number Formatting
medium
✓
Number to Words
hard
Number checks in a range
✓
Palindrome Numbers in a Range
easy
✓
Prime Numbers up to N
medium
✓
Armstrong Numbers up to N
medium
✓
Perfect Numbers up to N
medium
✓
Twin Primes up to N
medium
even odd sign
✓
Even or Odd Number
beginner
✓
Positive, Negative or Zero
beginner
✓
Sum of Even and Odd Digits
easy
digits
✓
Count Digits of a Number
beginner
✓
Sum of Digits
beginner
✓
Reverse a Number
easy
✓
Product of Digits
easy
✓
Largest and Smallest Digit
easy
✓
Frequency of Each Digit
medium
✓
Swap First and Last Digit
medium