Prime numbers between 7801 and 7,900
There are 10 prime numbers between 7801 and 7,900: 7817, 7823, 7829, 7841, 7853, 7867, 7873, 7877, 7879, 7883.
How to work it out
- 1
A prime has exactly two factors, 1 and itself. To list them, cross out multiples of 2, then 3, then 5, and so on up to ā7900 ā 88.9 (the sieve of Eratosthenes). What is left are the primes.
- 2
That leaves 10 primes between 7801 and 7,900, with a total of 78,542.
- 3
The biggest gap between neighbouring primes in this range is 14, after 7853 (the next prime is 7867). There are 1 twin prime pairs (primes 2 apart): (7877, 7879).
How many primes in each part
| Range | Primes | Share of the numbers |
|---|---|---|
| 7,801 to 7,810 | 0 | 0% |
| 7,811 to 7,820 | 1 | 10% |
| 7,821 to 7,830 | 2 | 20% |
| 7,831 to 7,840 | 0 | 0% |
| 7,841 to 7,850 | 1 | 10% |
| 7,851 to 7,860 | 1 | 10% |
| 7,861 to 7,870 | 1 | 10% |
| 7,871 to 7,880 | 3 | 30% |
| 7,881 to 7,890 | 1 | 10% |
| 7,891 to 7,900 | 0 | 0% |
Questions
How many prime numbers are there between 7801 and 7,900?
10.
What is the biggest prime number below 7,900?
7883.
What is the first prime number after 7800?
7817.