Mathematically 89

Eighty Nine (89)

1. It is a Fibonacci prime number.
1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89…

2. The inverse of 89 gives a fraction with a sequence of 44 recurring digits.
1/89 = 0. 01123595505617977528089887640449438202247191…
The best part of the result is that this number is the sum of the sequence of number from the Fibonacci series where by each number moves a decimal point to the right.
0.01 + 0.001 + 0.0002 + 0.00003 +0.000005 +0.0000008 +0.00000013 +0.000000021 + 0.0000000034 +…=0.011235955---

3. The first pair of consecutive prime that differ by 8 is 89 and 97.

4. It is a Markov number discovered by Andrey Markoff. A Markov number is a positive integer x, y or z such that-
x^3 +y^3+z^3 = 3xyz

The first ten Markov numbers are 1, 2, 5, 13, 29, 34, 89, 169, 194 and 233.

5. It is a Chen prime named after Chen Jingrun. A number p is a Chen prime if p+2 is either a prime or a product of two primes. The first ten Chen primes are- 2, , 5, 7, 11, 13, 17, 19, 23 and 29.

6. The atomic number of Actinium is 89.

Dr Rajesh K Thakur
rkthakur1974@gmail.com