# 224 (number)

224 (two hundred [and] twenty-four) is the natural number following 223 and preceding 225.

 ← 223 224 225 →
Cardinaltwo hundred twenty-four
Ordinal224th
(two hundred twenty-fourth)
Factorization25 × 7
PrimeNo
Greek numeralΣΚΔ´
Roman numeralCCXXIV
Binary111000002
Ternary220223
Octal3408
Duodecimal16812

224 is a practical number,[1] and a sum of two positive cubes 23 + 63.[2]

224 is the smallest k with λ(k) = 24, where λ(k) is the Carmichael function.[3]

The mathematician and philosopher Alex Bellos suggested in 2014 that a candidate for the lowest uninteresting number would be 224 because it was, at the time, "the lowest number not to have its own page on Wikipedia".[4]

## References[]

1. ^ Sloane, N. J. A. (ed.). "Sequence A005153 (Practical numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
2. ^ Sloane, N. J. A. (ed.). "Sequence A003325 (Numbers that are the sum of 2 positive cubes)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
3. ^ Sloane, N. J. A. (ed.). "Sequence A141162 (Smallest k such that lambda(k) = n)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
4. ^ Bellos, Alex (June 2014). The Grapes of Math: How Life Reflects Numbers and Numbers Reflect Life. illus. The Surreal McCoy (1st Simon & Schuster hardcover ed.). N.Y.: Simon & Schuster. pp. 238 & 319 (quoting p. 319). ISBN 978-1-4516-4009-0.