Properties of the Number 20953

Twenty Thousand Nine Hundred Fifty-Three

Basics

Value: 20952 → 20953 → 20954

Parity: odd

Prime: No

Previous Prime: 20947

Next Prime: 20959

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 23 × 911

Divisors: 1, 23, 911, 20953

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101000111011001

Octal: 50731

Duodecimal: 10161

Hexadecimal: 51d9

Square: 439028209

Square Root: 144.75151121836345

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

T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 0 horizontally and 0 0 1 vertically. A207088

Semiprimes in A033951. A113691

Denominators of continued fraction convergents to sqrt(766). A42477

a(n) = 2·prime(n)² - prime(n+1)². A64051

Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n-1)*b(n-2), where a(0) = 1, a(1) = 3, a[2] = 5, b(0) = 2, b(1) = 4, and (a(n)) and (b(n)) are increasing complementary sequences. A295364

Numbers k such that φ(k) > φ(k+1) > φ(k+2) > φ(k+3) where φ is the Euler totient function (A000010). A326817

Sum of squares of digits of n is equal to the largest prime factor of n reversed, where the largest prime factor is not a palindrome. A74303

Multiples of 23 whose digit reversal + 1 is also a multiple of 23. A166393

Number of (n+2) X 7 binary arrays with every 3 X 3 subblock commuting with each horizontal and vertical neighbor 3 X 3 subblock. A190029

Number of n X 3 0..1 arrays avoiding 0 0 0 horizontally and 0 0 1 vertically. A207083