247 (number)

247 (two hundred [and] forty-seven) is the natural number following 246 and preceding 248.

In mathematics[]

247 is:

• a semiprime.
• a brilliant number (the product of two primes with the same number of digits).^[1]
• a pentagonal number.^[2]
• palindromic in bases 18 (DD₁₈) and 246 (11₂₄₆).
• a Harshad number in bases 10, 14, 19, 20, 27, 39, 40, 58, 77, 79, 115, 118, 229 and 235.
• the smallest number which can be expressed as the difference between two integers that contain together all digits 0–9. i.e. 247 = 50123 - 49876.^[3]
• The mathematician and philosopher Alex Bellos suggested in 2014 that a candidate for the lowest uninteresting number would be 247 because it was, at the time, "the lowest number not to have its own page on Wikipedia".^{[4][nb 1]} The lowest uninteresting number would by itself be interesting.

In other fields[]

• Sometimes used as an alternative to 24/7, an abbreviation which means "24 hours a day, 7 days a week".^{[example needed]}
• Approximate number of acres in a square kilometer (1 km² ≈ 247.10538 acres).

Notes[]

References[]