Number of the day: 6457

Sophie Germain was born on this day 245 years ago.

Alexander Craig Aitken was born on this day 126 years ago.

Properties of the number 6457:

6457 is a cyclic number.
6457 = 11 × 587 is semiprime and squarefree.
6457 has 2 distinct prime factors, 4 divisors, 27 antidivisors and 5860 totatives.
6457 has a semiprime digit sum 22 in base 10.
6457 = 3229² - 3228² = 299² - 288² is the difference of 2 nonnegative squares in 2 ways.
6457 is the difference of 2 positive pentagonal numbers in 2 ways.
6457 = 7² + 18² + 78² is the sum of 3 positive squares.
6457² is the sum of 3 positive squares.
6457 is a proper divisor of 67²⁹³ - 1.
6457 is an emirpimes in (at least) the following bases: 3, 4, 5, 6, 7, 8, 9, 14, 16, 23, 24, 27, 29, 35, 37, 39, 43, 44, 51, 52, 53, 57, 58, 60, 64, 70, 75, 77, 78, 81, 85, 87, 88, 94, and 97.
6457 is palindromic in (at least) the following bases: 26, 30, and -20.
6457 in base 19 = hgg and consists of only the digits 'g' and 'h'.
6457 in base 26 = 9e9 and consists of only the digits '9' and 'e'.
6457 in base 29 = 7jj and consists of only the digits '7' and 'j'.
6457 in base 30 = 757 and consists of only the digits '5' and '7'.

The number 6457 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A006457: Number of elements in Z[ i ] whose `smallest algorithm' is <= n.
A023149: Numbers k such that prime(k) == 7 (mod k).
A025235: a(n) = (1/2)*s(n+2), where s = A014431.
A068575: Numbers n such that, as strings, n is a substring of prime(n).
A243044: T(n,k)=Number of length n+3 0..k arrays with no four elements in a row with pattern abab (with a!=b) and new values 0..k introduced in 0..k order
A264099: Number of active (ON,black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 363", based on the 5-celled von Neumann neighborhood.
A266778: Molien series for invariants of finite Coxeter group A_9.
A273646: Number of active (ON,black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 817", based on the 5-celled von Neumann neighborhood.
A326235: Numbers n such that N = (35n)^6 is a twin rank (A002822: 6N +- 1 are twin primes).
A338453: Starts of runs of 3 consecutive numbers with the same total binary weight of their divisors (A093653).