Number of the day: 27243

John von Neumann was born on this day 115 years ago.

Properties of the number 27243:

27243 = 3³ × 1009 is the 24260^th composite number and is not squarefree.
27243 has 2 distinct prime factors, 8 divisors, 17 antidivisors and 18144 totatives.
27243 = 3³ + 6³ + 30³ = 12³ + 18³ + 27³ is the sum of 3 positive cubes in 2 ways.
27243 = 13622² - 13621² = 4542² - 4539² = 1518² - 1509² = 518² - 491² is the difference of 2 nonnegative squares in 4 ways.
27243 is the difference of 2 positive pentagonal numbers in 1 way.
27243 = 7² + 25² + 163² is the sum of 3 positive squares.
27243² = 15093² + 22680² is the sum of 2 positive squares in 1 way.
27243² is the sum of 3 positive squares.
27243 is a proper divisor of 337⁹ - 1.
27243 = '2' + '7243' is the concatenation of 2 prime numbers.
27243 in base 3 = 1101101000 and consists of only the digits '0' and '1'.

The number 27243 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A002255: Numbers n such that 7*4^n + 1 is prime.
A009474: a(n) is the concatenation of n and 9n.
A191573: Number of n X n symmetric binary matrices with each 1 adjacent to no more than 5 knight-move neighboring 1s
A225967: Number of permutations of [n] having exactly 6 strong fixed blocks.
A228064: Difference between the number of primes with n digits (A006879) and the nearest integer to F[4n](S(n)), where F[4n](x) are Fibonacci polynomials and S(n) = Sum_{i=0..3} (C(i)*(log(log(A*(B+n^2))))^i) (see A228063).