# 131

This number is a prime.

Just showing those entries submitted by 'Silva': (Click here to show all) The sum of three two-digit primes (31 + 41 + 59) whose concatenation is the decimal expansion of π. [Silva] 131 = (1^0+3^0+1^0) + (1^1+3^1+1^1) + (1^2+3^2+1^2) + (1^3+3^3+1^3) + (1^4+3^4+1^4). Note that the summands are all primes. [Silva] 131 and the next prime after it are the first pair of consecutive primes where we can find another pair of consecutive primes by concatenating each term's end digits. [Silva] The smallest palindromic prime that yields another if the sum of digits of its consecutive digits is sandwiched between each of the corresponding consecutive digits (i.e., 131 becomes 14341). [Silva] The 1st prime after p(31) is 131. [Silva] The smallest palindromic prime equal to a prime plus the sum of all previous composite numbers, i.e., 19+18+16+15+14+12+10+9+8+6+4. [Silva] The smallest palindromic prime that is the sum of three consecutive primes (41+43+47). [Silva] Sum of the factorials of the first six Fibonacci numbers: 0!+1!+1!+2!+3!+5! = 131. [Silva] 131 is the sum of three two-digit primes which appear as first digits of the decimal expansion of pi: 31+41+59. [Silva]

(There are 3 curios for this number that have not yet been approved by an editor.)