1021

Previous  ... Next

Number

$1021$ (one thousand and twenty-one) is:

The $172$nd prime number

The $9$th prime $p$ such that $p \# + 1$, where $p \#$ denotes primorial (product of all primes up to $p$) of $p$, is prime:

$2$, $3$, $5$, $7$, $11$, $31$, $379$, $1019$, $1021$

The smaller of the $17$th pair of primes whose prime gap is $10$:

$1031 - 1021 = 10$

The $35$th emirp after $13$, $17$, $31$, $37$, $\ldots$, $733$, $739$, $743$, $751$, $761$, $769$, $907$, $937$, $941$, $953$, $967$, $971$, $983$, $991$, $1009$

The larger of the $36$th pair of twin primes:

$1021 - 1019 = 2$

Also see

• Previous  ... Next: Prime Gaps of 10

• Previous  ... Next: Emirp

• Previous  ... Next: Prime Number
• Previous  ... Next: Twin Primes
• Previous  ... Next: Sequence of Prime Primorial plus 1