“99 (number)”的意思、由来-开放百科全书

词条

99 (number)

释义

In mathematics
In science
References
External links

{{about|the number|other uses|99 (disambiguation)}}{{Infobox number
| number = 99
| divisor = 1, 3, 9, 11, 33, 99
| lang1 = Chinese/Japanese
/Korean numeral
| lang1 symbol = 九十九
}}

99 (ninety-nine) is the natural number following 98 and preceding 100.

In mathematics

99 is:

a Kaprekar number^[1]
a lucky number
a palindromic number
the ninth repdigit
the sum of the cubes of three consecutive integers: 99 = 2³ + 3³ + 4³
the sum of the sums of the divisors of the first 11 positive integers.^[2]
the highest two digit number in decimal.

In science

The atomic number of Einsteinium, an actinide.

References

1. ^{{Cite web|url=https://oeis.org/A006886|title=Sloane's A006886 : Kaprekar numbers|last=|first=|date=|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|access-date=2016-05-28}}
2. ^{{Cite OEIS|A024916|name=sum_{k=1..n} sigma(k) where sigma(n) = sum of divisors of n}}

External links

1 : Integers

随便看

开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。