Properties of the Number 3985

Three Thousand Nine Hundred Eighty-Five

Basics

Value: 3984 → 3985 → 3986

Parity: odd

Prime: No

Previous Prime: 3967

Next Prime: 3989

Digit Sum: 25

Digital Root: 7

Palindrome: No

Factorization: 5 × 797

Divisors: 1, 5, 797, 3985

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 111110010001

Octal: 7621

Duodecimal: 2381

Hexadecimal: f91

Square: 15880225

Square Root: 63.12685640834652

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

G.f. satisfies: A(x) = (1 + x·A(x))*(1 + x³*A(x)²). A192415

T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with no element unequal to a strict majority of its horizontal, diagonal and antidiagonal neighbors, with values 0..2 introduced in row major order. A231396

T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with every element equal to some horizontal, diagonal or antidiagonal neighbor, with top left element zero. A232076

This table shows the coefficients of sum formulas of n-th Fibonacci numbers (A000045). The k-th row (k>=1) contains T(i,k) for i=1 to k, where k=[2·n+1+(-1)^n-1]/4 and T(i,k) satisfies F(n)= ∑_i=1..k T(i,k) * n^k-i/(k-1)!. A99731

T(n,k) is the number of 0..k arrays x(0..n+1) of n+2 elements without any interior element greater than both neighbors. A200886

a(n) = 2^prime(n-1) mod prime(n)². A196202

Irregular array read by rows in which row floor(k/3)+1, where gcd(k,6)=1, lists the smallest elements, in ascending order, of conjecturally all primitive cycles of positive integers under iteration by the 3x+k function. A226607

Number of ways to write n as an ordered sum of 5 primes. A340961

Integers of the form c(n)/b(n) where c(n+1)=c(n)+(n+1)⁴ with c(0)=1 and b(n+1)=b(n)+(n+1)² with b(0)=1. A119617

a(n) = 15·n² + 9·n + 1. A134153