Properties of the Number 7381

Seven Thousand Three Hundred Eighty-One

Basics

Value: 7380 → 7381 → 7382

Parity: odd

Prime: No

Previous Prime: 7369

Next Prime: 7393

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 11 ² × 61

Divisors: 1, 11, 61, 121, 671, 7381

Polygonal

Triangular: Yes

Square: No

Pentagonal: No

Hexagonal: Yes

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 1110011010101

Octal: 16325

Duodecimal: 4331

Hexadecimal: 1cd5

Square: 54479161

Square Root: 85.9127464349732

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) = numerator of harmonic number H(n) = ∑_i=1..n 1/i. A1008

a(n) = (9ⁿ - 1)/8. A2452

Triangular array: T(n,k) counts the partitions of the set [n] into k odd sized blocks. A136630

Centered 9-gonal (also known as nonagonal or enneagonal) numbers. Every third triangular number, starting with a(1)=1. A60544

a(n) = n²*(n² + 1)/2. A37270

Pseudoprimes to base 3. A5935

Numerator of the polynomial A_l(x) = ∑_d=1..l-1 x^l-d/d for index l=2n+1 evaluated at x=1. A145609

a(n) = n⁴ + n³ + n² + n + 1. A53699

a(n) = (2·n+1)*(4·n+1). A14634

Triangle of Gaussian binomial coefficients [ n,k ] for q = 9. A22173