400 (number) third perfect number, a number whose divisors add up to the actual number (1+2+4+8+16+31+62+124+248=496). 497 = 7 × 71, sum of five consecutive primes (89 + 97 + 101 + 103 + 107) 498 = 2 × 3 × 83, sphenic number, untouchable number, admirable number, abundant number A prime number, Chen prime 400 (number) 400 (four hundred) is the natural number following 399 and preceding 401. 400 is the square of 20. 400 is the sum of the powers of 7 from 0 to 3, thus making it a repdigit in base 7 (1111). A circle is divided into
The whole nine yards origin, though many early published quotations are now available for study. A vast number of explanations for this phrase has been suggested; many of these are no longer viable in light of what is now known about the phrase's history. The whole nine yards "The whole nine yards" or "the full nine yards" is a colloquial American English phrase meaning "everything, the whole lot" or, when used as an adjective, "all the way", as in, "The Army came out and gave us the whole nine yards on how they use space systems." Its origin is unknown and has been described