Properties of the Number 15821

Fifteen Thousand Eight Hundred Twenty-One

Basics

Value: 15820 → 15821 → 15822

Parity: odd

Prime: No

Previous Prime: 15817

Next Prime: 15823

Digit Sum: 17

Digital Root: 8

Palindrome: No

Factorization: 13 × 1217

Divisors: 1, 13, 1217, 15821

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 11110111001101

Octal: 36715

Duodecimal: 91A5

Hexadecimal: 3dcd

Square: 250304041

Square Root: 125.78155667664477

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

Shifts one place left under 4th-order binomial transform. A4213

Triangle read by rows. T(n, k) = kⁿ * BellPolynomial(n, 1/k) for k > 0, if k = 0 then T(n, k) = kⁿ. A350260

Square array read by antidiagonals upwards: T(n,k) = ∑_j=1..k n^k-j*Stirling₂(k,j) (n >= 0, k >= 1). A241578

Square array read by antidiagonals downwards: T(n,k) = ∑_j=1..k n^k-j*Stirling₂(k,j) (n >= 0, k >= 1). A241579

Expansion of 1 / ((1-x) * (1-3·x) * (1-10·x)). A16215

Triangle, generated from A111579. A111673

Hypotenuses c of primitive Pythagorean Triples (a,b,c) such that 2·a+1, 2·b+1 and 2·c+1 are primes. A165238

Solution of the complementary equation a(n) = 2·a(n-1) - a(n-2) + b(n-1) + 1, where a(0) = 1, a(1) = 2, b(0) = 3, and (a(n)) and (b(n)) are increasing complementary sequences. A294869

Expansion of e.g.f. exp(x) / (1 - x·exp(3·x)). A368292

Number of partitions of n with prime rank. A363241