Properties of the Number 15621

Fifteen Thousand Six Hundred Twenty-One

Basics

Value: 15620 → 15621 → 15622

Parity: odd

Prime: No

Previous Prime: 15619

Next Prime: 15629

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 3 × 41 × 127

Divisors: 1, 3, 41, 123, 127, 381, 5207, 15621

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 11110100000101

Octal: 36405

Duodecimal: 9059

Hexadecimal: 3d05

Square: 244015641

Square Root: 124.9839989758689

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

"Orderly" Friedman numbers (or "good" or "nice" Friedman numbers): Friedman numbers (A036057) where the construction digits are used in the proper order. A80035

a(n) = nⁿ⁺¹ - n + 1. A14293

First trisection of A061037 (Balmer line series of the hydrogen atom). A142590

a(n) = ∑_{1 <= x₁, x₂, x₃, x₄, x₅ <= n} n/gcd(x₁, x₂, x₃, x₄, x₅, n). A371878

Square array T(n,k), n >= 1, k >= 1, read by antidiagonals, where T(n,k) = ∑_{1 <= x₁, x₂, ..., x_k <= n} n/gcd(x₁, x₂, ..., x_k, n). A372968

a(n) = (4·n+3)*(4·n+7). A85027

a(n) = Fibonacci(n) mod n³. A132636

Positive solutions of Monkey and Coconuts Problem for the classic case (5 sailors, 1 coconut to the monkey): a(n) = 15625·n - 4 for n >= 1. A254029

a(n) = 5ⁿ - 4. A164785

Monotonic ordering of nonnegative differences 5ⁱ-4^j, for 40>= i>=0, j>=0. A192162