Compare 21 vs 37

Property2137
Typesemiprimeprime
Unique factors21
Total factors21
Prime factorization31 × 71371
Prime factorization3 × 737
Divisors count42
Divisors1, 3, 7, 211, 37
Number of properties118
Chen primes 12th
Cousin primes (1st member) 5th
Cuban primes 1 3rd
Emirps 4th
Good primes 5th
Isolated primes 3rd
Left-truncatable primes 8th
Lucky primes 5th
Pierpont primes 8th
Primes 12th
Prime triplets (1st member) 6th
Pythagorean primes 5th
Right-truncatable primes 8th
Semiprimes7th 
Sexy primes (1st member) 8th
Sexy primes (2nd member) 7th
Sexy prime triplets (2nd member) 5th
Solinas primes 11th
Two-sided primes 6th
Roman numberalsXXIXXXVII
Base 21010121001012
Base 3210311013
Base 411142114
Base 54151225
Base 63361016
Base 7307527
Base 8258458
Base 9239419
Base 1021103710
Base 111a113411
Base 1219123112
Base 1318132b13
Base 1417142914
Base 1516152715
Base 1615162516
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