Properties of the Number 21487

Twenty-One Thousand Four Hundred Eighty-Seven

Basics

Value: 21486 → 21487 → 21488

Parity: odd

Prime: Yes

Previous Prime: 21481

Next Prime: 21491

Digit Sum: 22

Digital Root: 4

Palindrome: No

Factorization: 21487

Divisors: 1, 21487

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101001111101111

Octal: 51757

Duodecimal: 10527

Hexadecimal: 53ef

Square: 461691169

Square Root: 146.58444665106867

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

Initial term in sequence of four consecutive primes separated by 3 consecutive differences each <=6 (i.e., when d=2,4 or 6) and forming d-pattern=[4,2,6]; short d-string notation of pattern = [426]. A78850

Second member of a sexy prime quadruple: value of p+6 such that p, p+6, p+12 and p+18 are all prime. A46122

Number of ordered triples (w,x,y) with all terms in {1,...,n} and w³ >= x³ + y³. A211651

Primes p such that 6p + 1 and (p-1)/6 are primes. A85957

Largest prime == 7 (mod 8) with class number 2n+1. A2147

Number of Twopins positions. A5691

Primes p such that p·floor(p/2)-2 and p·floor(p/2)+2 are also prime numbers. A164621

Primes p such that the differences between the 5 consecutive primes starting with p are (4,2,6,4). A78953

Primes p such that p + 2², p + 4² and p + 6² are also primes. A92475

Primes of the form 4k+3 generated recursively: a(1)=3, a(n)= Min{p; p is prime; Mod[p,4]=3; p∣4Q²-1}, where Q is the product of all previous terms in the sequence. A217759