Properties of the Number 8221

Eight Thousand Two Hundred Twenty-One

Basics

Value: 8220 → 8221 → 8222

Parity: odd

Prime: Yes

Previous Prime: 8219

Next Prime: 8231

Digit Sum: 13

Digital Root: 4

Palindrome: No

Factorization: 8221

Divisors: 1, 8221

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10000000011101

Octal: 20035

Duodecimal: 4911

Hexadecimal: 201d

Square: 67584841

Square Root: 90.6697303403953

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: Yes

Friedman Number: No

Fermat Number: No

Cullen Number: No

OEIS Sequences

Primes with indices that are primes with prime indices. A38580

Primes or negative values of primes in the sequence b(n) = 47·n² - 1701·n + 10181, n >= 0. A50267

Primes with first digit 8. A45714

Primes prime(k) for which A049076(k) = 3. A49079

Class 5+ primes (for definition see A005105). A81633

Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k doubledescents (0 <= k <= n-2). We say that i is a doubledescent (also called a double fall) of a permutation p if p(i) > p(i+1) > p(i+2). A162975

Primes that divide at least one term of Sylvester's sequence s = A000058: s(n+1) = s(n)² - s(n) + 1, s(0) = 2. A7996

Least prime in A031928 (lesser of 10-twins) whose distance to the next 10-twin is 6·n. A52354

Magnanimous primes: primes with the property that inserting a "+" in any place between two digits yields a sum which is prime. A89392

Primes p such that (p+1)/2 and (p+2)/3 are also primes. A36570