Properties of the Number 30381

Thirty Thousand Three Hundred Eighty-One

Basics

Value: 30380 → 30381 → 30382

Parity: odd

Prime: No

Previous Prime: 30367

Next Prime: 30389

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 3 × 13 × 19 × 41

Divisors: 1, 3, 13, 19, 39, 41, 57, 123, 247, 533

Polygonal

Triangular: Yes

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 111011010101101

Octal: 73255

Duodecimal: 156B9

Hexadecimal: 76ad

Square: 923005161

Square Root: 174.30146298869667

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(n) = n*(n - 1)*(n + 2)/2. A77414

Two-column table read by rows: Primitive distinct pairs that have the same value of φ, σ, and τ. A322688

Triangular numbers with property that digits alternate in parity. A68882

2nd elementary symmetric function of the first n+1 positive integers congruent to 2 mod 3. A24391

Smallest triangular number which is a multiple (>1) of the n-th triangular number. A68084

Largest coefficient in expansion of (1 + x + x² + ... + x^n-1)⁵ = ((1-xⁿ)/(1-x))⁵, i.e., the coefficient of x^floor(5*(n-1)/2) and of x^ceiling(5*(n-1)/2); also number of compositions of floor(5*(n+1)/2) into exactly 5 positive integers each no more than n. A77044

Number of ordered quintuples (a,b,c,d,e), -n <= a,b,c,d,e <= n, such that a+b+c+d+e = 0. A83669

G.f.: 1/((1-x)*(1-x²))⁶. A38166

Numbers k such that k and 10·k are both triangular numbers. A68085

Triangular numbers t such that t+10 is a prime. A129755