This nBAB for

`was created because MathBabbler was in the mood to create a nBAB and`

145`was the smallest number without a nBAB.`

145MathBabbler Number Analyst (MBNA) output: ========================================= 145 is a natural, whole, integer 145 is odd 145 proper divisors are: 1,5,29, 145 is deficient (sum of divisors is 35) 145 is unhappy 145 is not a Harshad number 145 is not prime 145 has the prime factors: 5*29 (sum=34) 145 is semiprime (biprime or 2-almost prime) 145 sum of prime factors is: 34 145 is ThurmNumber 145 is a Leyland number (3^4+4^3) 145 in octal is 0221 145 in hexadecimal is 0x91 145 in binary is 10010001 (is odious) 145 nearest square numbers: -1...24 (144...169 [13]) sqrt(145) = 12.0416 ln(145) = 4.97673 log(145) = 2.16137 145 reciprocal is .00689655172413793103448275862068 145! is 8.04793e+251 145 is 46.1549 Pi years 145 is 7 score and 5 years 145 written as a Roman numeral is CXLV 145 = 73^2 - 72^2 and 73 + 72 = 145NumberGossip.com reported that "

`is the smallest number (besides the trivial cases of 1 and 2) that is the sum of the factorials of its digits (1!+4!+5!).`

145NumDic.com reported that

`is a`

145pentagonal numberand that it is the sum of two squares (9^2+8^2).OEIS.org::id:A000326.

Pentagonal numbers: n(3n-1)/2 0, 1, 5, 12, 22, 35, 51, 70, 92, 117,145, 176, 210, 247, 287, 330, 376, 425, 477, 532, 590, 651, 715, 782, 852, 925, 1001, 1080, 1162, 1247, 1335, 1426, 1520, 1617, 1717, 1820, 1926, 2035, 2147, ... n is a pentagonal number if... (sqrt(24n+1) + 1)/6 evaluates to a whole numberThe creation of this nBAB for the number

`prompted MathBabbler to write this C++ program that checks if a number is a`

145pentagonal number. This program has been added to the MBNA (MathBabbler Number Analyst).

**Creator:** Gerald Thurman
[gthurman@gmail.com]

**Created:** 11 March 2010

This work is licensed under a Creative Commons Attribution 3.0 United States License.