7774777

Properties

Appears in sequences

• Primes that contain digits 4 and 7 only.at n=20A020465
• Palindromic wing primes (a.k.a. near-repdigit palindromic primes) of the general form r*(10^d - 1)/9 + (m-r)*10^floor(d/2) where d is the number of digits (an odd number > 1), r is the repeated digit, and m (different from r) is the middle digit.at n=26A077798
• Palindromic primes in which a single digit is sandwiched between strings of 7's.at n=8A088283
• Primes p such that one digit appears exactly six times together with a single different digit.at n=26A257937
• Palindromic wing primes that are also Lychrel candidates.at n=0A320516
• a(n) = 7*(10^(2n+1)-1)/9 - 3*10^n.at n=3A332174
• Prime numbersat n=525596