Number reference
67 explained.
67: sixty-seven, prime; factors, prime factorization, roots, binary, hexadecimal, and digit properties.
Identity and representations
- Written form
- sixty-seven
- Classification
- prime
- Factors
- 1, 67
- Prime factorization
- 67
- Square root
- 8.185353
- Cube root
- 4.061548
- Binary
- 1000011
- Octal
- 103
- Hexadecimal
- 43
- Roman numeral
- LXVII
- Digit sum
- 13
- Digital root
- 4
What makes 67 notable
- Prime. 67 is prime: it has exactly two divisors, 1 and itself, so it cannot be split into equal whole-number groups any other way.
67 in everyday use
Sixty-seven is the atomic number of holmium, a rare earth with the strongest magnetic moment of any natural element, used in the pole pieces of powerful magnets. In the ASCII character set, code 67 is the capital letter C, so every text file with a C in it stores a 67 somewhere. The summer of 1967 is remembered as the Summer of Love, and Canada celebrated its centennial that year with Expo 67 in Montreal.
Sixty-seven is the nineteenth prime and an isolated one, since 65 and 69 are both composite. It is the largest prime that cannot be written as a sum of distinct squares: every prime above it can be. It leaves a remainder of 3 when divided by 4, so it is not a sum of two squares either. In binary it is 1000011.
Nearby numbers
How to read this page
Because 67 is prime, the factor list stops at 1 and 67 itself, so it cannot be shared into equal whole-number groups. That is also what makes it useful as a building block: every larger number with 67 in its prime factorisation inherits it from here.
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