Properties of the Number 21455

Twenty-One Thousand Four Hundred Fifty-Five

Basics

Value: 21454 → 21455 → 21456

Parity: odd

Prime: No

Previous Prime: 21433

Next Prime: 21467

Digit Sum: 17

Digital Root: 8

Palindrome: No

Factorization: 5 × 7 × 613

Divisors: 1, 5, 7, 35, 613, 3065, 4291, 21455

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101001111001111

Octal: 51717

Duodecimal: 104BB

Hexadecimal: 53cf

Square: 460317025

Square Root: 146.47525388269514

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) = n*(n² + 1)/2. A6003

Rhombic dodecahedral numbers: a(n) = n⁴ - (n - 1)⁴. A5917

a(n) = (1/2)*(n³ + n*(n mod 2)). A317614

Sum of terms in each group in A074147. A74149

T(n,k)=Number of nXk 0..3 arrays with no element equal to zero plus the sum of elements to its left or zero plus the sum of the elements above it or one plus the sum of the elements diagonally to its northwest, modulo 4. A240327

Number of pairs of orientable necklaces with n beads and up to 3 colors; i.e., turning the necklace over does not leave it unchanged. The turned-over necklace is not included in the count. A278639

G.f. satisfies A(x) = exp( ∑_k>=1 A(x^k) * x^k/(k * (1 + 2·x^k)) ). A363580

Row sums of triangle A074135. A74132

Number of (w,x,y) with all terms in {0,...,n} and even range. A212975

Smallest k<3·2ⁿ such that 3·2ⁿ+k is the smallest of four consecutive primes in arithmetic progression or 0 if no solution. A230852