Properties of the Number 16721

Sixteen Thousand Seven Hundred Twenty-One

Basics

Value: 16720 → 16721 → 16722

Parity: odd

Prime: No

Previous Prime: 16703

Next Prime: 16729

Digit Sum: 17

Digital Root: 8

Palindrome: No

Factorization: 23 × 727

Divisors: 1, 23, 727, 16721

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100000101010001

Octal: 40521

Duodecimal: 9815

Hexadecimal: 4151

Square: 279591841

Square Root: 129.30970574554718

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(1)=1, a(n)=a(n-1)+n if n even, a(n)=a(n-1)+n² if n is odd. A136047

Number of bracketings of 0⁰^0^...⁰, with n 0's, giving the result 0, with conventions that 0⁰ = 1⁰ = 1¹ = 1, 0¹ = 0. A55113

Triangle of coefficients of polynomials defined by Binet form: P(n,x) = ((x + d)ⁿ - (x - d)ⁿ)/(2·d), where d = sqrt(x+4). A162517

Odd composite integers m such that A087130(m) == 5 (mod m). A335671

Constant term of the reduction by x² -> x+1 of the polynomial p(n,x) defined below in Comments. A192746

Sums of 5 distinct powers of 4. A38473

Number of ordered ways of writing n as a sum of n tetrahedral numbers. A303170

Concatenate n and the sum of factorials of the digits of n. A109016

Semiprime terms in A136047. A136048

Records in A214323. A214324