Properties of the Number 21379

Twenty-One Thousand Three Hundred Seventy-Nine

Basics

Value: 21378 → 21379 → 21380

Parity: odd

Prime: Yes

Previous Prime: 21377

Next Prime: 21383

Digit Sum: 22

Digital Root: 4

Palindrome: No

Factorization: 21379

Divisors: 1, 21379

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101001110000011

Octal: 51603

Duodecimal: 10457

Hexadecimal: 5383

Square: 457061641

Square Root: 146.21559424356897

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 arrays of the minimum value of corresponding elements and their horizontal or antidiagonal neighbors in a random 0..2 nXk array. A217964

Primes p whose period of reciprocal equals (p-1)/7. A56212

T(n,k)=Number of nXk 1..4 arrays with no element with value z exactly a city block distance of z from another element with value z. A210788

The 180-degree spoke (or ray) of a hexagonal spiral of Ulam. A244806

Prime time primes (of the form HMMSS with primes H < 24 and MM, SS < 60) such that the corresponding number of seconds after midnight is also prime. A295000

Prime time primes on 6-digit clocks, second definition: primes of the form HMMSS where H, MM, SS are primes, H < 24, MM and SS < 60. A295013

Let F(g,p) be the frequency of g up to prime nextprime(p+1). Primes p such that F(2,p) = F(4,p) and g = 2 or 4. A274122

Number of vertices in a graph of n adjacent rectangles in a row with all possible diagonals drawn, as in A306302, but without the rectangles' edges which are perpendicular to the row. A369176

Prime(n) and prime(n+3) use the same digits. A69795

Prime mean of 8 horizontal, vertical and main diagonal sums associated with primes in A094454. A94455