Properties of the Number 2105

Two Thousand One Hundred Five

Basics

Value: 2104 → 2105 → 2106

Parity: odd

Prime: No

Previous Prime: 2099

Next Prime: 2111

Digit Sum: 8

Digital Root: 8

Palindrome: No

Factorization: 5 × 421

Divisors: 1, 5, 421, 2105

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100000111001

Octal: 4071

Duodecimal: 1275

Hexadecimal: 839

Square: 4431025

Square Root: 45.880278987817846

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

Numbers n such that the decimal expansions of both n and n² have 0 as smallest digit and 5 as largest digit. A256631

a(0)=0, a(1)=1, a(2)=1, a(3)=1, a(n) = a(n-3) + a(n-4) for n > 3. A79398

Starts of runs of 3 consecutive positive negabinary-Niven numbers (A331728). A331822

5-Knödel numbers. A50993

Odd interprimes not divisible by 3. A72573

Number of symmetric ways of folding a strip of n labeled stamps. A560

Square spiral of sums of selected preceding terms, starting at 1. A141481

T(n,k)=Number of nXk 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of the elements above it or zero plus the sum of the elements diagonally to its northwest, modulo 4. A240412

Short leg A of primitive Pythagorean triangles such that perimeter s is average of twin prime pairs, q=p+1, A=q²-p², C=q²+p², B=2·p*q, s=A+B+C; s -/+ 1 are primes. A155173

Fixed points in A376198. A376201