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Properties of the Number 27945

Twenty-Seven Thousand Nine Hundred Forty-Five

Basics

Value: 27944 → 27945 → 27946

Parity: odd

Prime: No

Previous Prime: 27943

Next Prime: 27947

Digit Sum: 27

Digital Root: 9

Palindrome: No

Factorization: 3 5 × 5 × 23

Divisors: 1, 3, 5, 9, 15, 23, 27, 45, 69, 81

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 110110100101001

Octal: 66451

Duodecimal: 14209

Hexadecimal: 6d29

Square: 780923025

Square Root: 167.16758058906038

Classification

Fibonacci: No

Bell Number: No

Factorial Number: No

Regular Number: No

Perfect Number: No

Special

Kaprekar Constant: No

Munchausen Constant: No

Armstrong Number: No

Kaprekar Number: No

Catalan Number: No

Vampire Number: No

Taxicab Number: No

Super Prime: No

Friedman Number: No

Fermat Number: No

Cullen Number: No

OEIS Sequences

a(n) = 3·a(n-1) + 3·a(n-2), a(0)=0, a(1)=3. A106435
T(n,k)=Number of (n+6)X(k+6) 0..1 matrices with each 7X7 subblock idempotent. A224588
T(n,k)=Number of 0..k arrays of length n with each element unequal to at least one neighbor, starting with 0. A221463
Numbers n such that the digits of σ(n) are exactly the same (albeit in different order) as the digits of φ(n), in base 10. A175795
a(n) = a(n-1) + 3·a(n-2) if n even, or 2·a(n-1) + 4·a(n-2) if n odd, starting with 0, 1. A299914
a(n) = A299914(2n). A299915
E.g.f. A(x) satisfies A(x) = exp( sin(x·A(x)) / A(x) ). A381148
Odd numbers divisible by exactly 7 primes (counted with multiplicity). A46320
Decimal numbers m such that the product of the binary string of m and the binary string of m in reverse contains the binary string of m as a substring. A342130
a(n) = 3*(3n-1 - 2n + 1)/2 - binomial(n,2), n >= 3. A363591