Number of the day: 7247

Benoit Mandelbrot was born on this day 96 years ago.

Properties of the number 7247:

7247 is a cyclic number.
7247 is the 927^th prime.
7247 has 9 antidivisors and 7246 totatives.
7247 has an oblong digit sum 20 in base 10.
Reversing the decimal digits of 7247 results in a semiprime.
7247 = 3624² - 3623² is the difference of 2 nonnegative squares in 1 way.
7247 is the sum of 2 positive triangular numbers.
7247 is the difference of 2 positive pentagonal numbers in 1 way.
7247 is not the sum of 3 positive squares.
7247² is the sum of 3 positive squares.
7247 is a proper divisor of 2³⁶²³ - 1.
7247 is an emirp in (at least) the following bases: 6, 7, 8, 13, 15, 18, 21, 23, 29, 31, 36, 38, 39, 43, 46, 53, 64, 65, 67, 68, 69, 70, 71, 79, 80, 81, 84, 89, 98, and 99.
7247 is palindromic in (at least) the following bases: -63, and -69.
7247 in base 15 = 2232 and consists of only the digits '2' and '3'.
7247 in base 19 = 1118 and consists of only the digits '1' and '8'.
7247 in base 42 = 44N and consists of only the digits '4' and 'N'.

The number 7247 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A026378: a(n) = number of integer strings s(0),...,s(n) counted by array T in A026374 that have s(n)=1; also a(n) = T(2n-1,n-1).
A045713: Primes with first digit 7.
A066179: Primes p such that (p-1)/2 and (p-3)/4 are also prime.
A073609: a(0) = 2; a(n) for n > 0 is the smallest prime greater than a(n-1) that differs from a(n-1) by a square.
A075421: Trajectory of n under the Reverse and Add! operation carried out in base 4 (presumably) does not reach a palindrome and (presumably) does not join the trajectory of any term m < n.
A104845: Primes from merging of 4 successive digits in decimal expansion of e.
A126791: Binomial matrix applied to A111418.
A141908: Primes congruent to 2 mod 23.
A198778: Primes from merging of 4 successive digits in decimal expansion of Euler-Mascheroni constant A001620.
A238583: Number T(n,k) of equivalence classes of ways of placing k 4 X 4 tiles in an n X 9 rectangle under all symmetry operations of the rectangle; irregular triangle T(n,k), n>=4, 0<=k<=2*floor(n/4), read by rows.