202

This number is a composite.

+ A semiprime palindrome equal to (2 + 3 + 5 + 7)2 - (22 + 32 + 52 + 72). It's the only such case for all primes < 2,000,000,000. [Trotter and De Geest]

+ 202^293 begins with the digits 293 (a prime). Note that 293^202 begins with the digits 202 (a palindrome). [Hartley]

+ 202 is the only known palindromic semiprime with following property: 202 = 2*101. Concatenate its prime factors (2101) then add the prime factors of 2101 (i.e., 11 + 191) to return to 202. No other such runs up to 100 million. [Luhn]

+ a(202) of OEIS sequence A358401 = 0. [Gaydos]

Printed from the PrimePages <primes.utm.edu> © G. L. Honaker and Chris K. Caldwell