# 2821

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## Summary

### Factorization

The number 2821 is a square-free number with prime factors 7, 13, and 31. The prime factorization is as follows:

### Properties and families

Property or family | Parameter values | First few members | Proof of membership/containment/satisfaction |
---|---|---|---|

Carmichael number | fifth among them | 561, 1105, 1729, 2465, 2821, 6601, [SHOW MORE]View list on OEIS |
The universal exponent is which divides 2821 - 1 = 2820. |

Poulet number (Fermat pseudoprime to base 2) | eleventh among them | 341, 561, 645, 1105, 1387, 1729, 1905, 2047, [SHOW MORE] View list on OEIS | follows from being a Carmichael number. |