Number of the day: 3207

Properties of the number 3207:

3207 = 3 × 1069 is semiprime and squarefree.
3207 has 2 distinct prime factors, 4 divisors, 9 antidivisors and 2136 totatives.
3207 has an oblong digit sum 12 in base 10.
Reversing the decimal digits of 3207 results in an emirpimes.
3207 = 1604² - 1603² = 536² - 533² is the difference of 2 nonnegative squares in 2 ways.
3207 is the sum of 2 positive triangular numbers.
3207 is the difference of 2 positive pentagonal numbers in 1 way.
3207 is not the sum of 3 positive squares.
3207² = 2193² + 2340² is the sum of 2 positive squares in 1 way.
3207² is the sum of 3 positive squares.
3207 is a proper divisor of 1889⁴ - 1.
3207 is an emirpimes in (at least) the following bases: 2, 5, 7, 9, 10, 11, 15, 36, 39, 42, 44, 46, 47, 48, 50, 58, 59, 60, 62, 63, 69, 73, 74, 75, 77, 89, 90, 96, and 99.
3207 is palindromic in (at least) the following bases: 17, and -36.
3207 in base 17 = b1b and consists of only the digits '1' and 'b'.
3207 in base 56 = 11F and consists of only the digits '1' and 'F'.

The number 3207 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A014670: G.f.: (1+x)*(1+x^3)*(1+x^5)*(1+x^7)*(1+x^9)/((1-x^2)*(1-x^4)*(1-x^6)*(1-x^8)*(1-x^10)).
A072475: Sum of next n composite numbers.
A124200: Numbers n such that 1 + n + n^3 + n^5 + n^7 + n^9 + n^11 + n^13 + n^15 + n^17 + n^19 + n^21 + n^23 + n^25 + n^27 + n^29 + n^31 + n^33 + n^35 + n^37 + n^39 + n^41 + n^43 is prime.
A137994: a(n) is the smallest integer > a(n-1) such that {Pi^a(n)} < {Pi^a(n-1)}, where {x} = x - floor(x), a(1)=1.
A207542: Number of solid standard Young tableaux with n cells.
A243577: Integers of the form 8k+7 that can be written as a sum of four distinct 'almost consecutive' squares.
A243580: Integers of the form 8k + 7 that can be written as a sum of four distinct squares of the form m, m + 1, m + 3, m + 5, where m == 2 (mod 4).
A293403: Greatest integer k such that k/n^2 < (3 + sqrt(5))/2.
A293405: The integer k that minimizes |k/n^2 - tau^2|, where tau = (1+sqrt(5))/2 (golden ratio).
A298791: Partial sums of A298789.