Properties of the Number 2639

Two Thousand Six Hundred Thirty-Nine

Basics

Value: 2638 → 2639 → 2640

Parity: odd

Prime: No

Previous Prime: 2633

Next Prime: 2647

Digit Sum: 20

Digital Root: 2

Palindrome: No

Factorization: 7 × 13 × 29

Divisors: 1, 7, 13, 29, 91, 203, 377, 2639

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101001001111

Octal: 5117

Duodecimal: 163B

Hexadecimal: a4f

Square: 6964321

Square Root: 51.37119815616529

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

Squarefree numbers with a divisor having the same sum of prime indices as their quotient. A357854

MM-numbers of labeled graphs with loops spanning an initial interval of positive integers. A320461

Triangular array T read by rows: T(n,0) = 1 for n >= 0; T(1,1) = 1; and for n >= 2, T(n,k) = T(n-1,k-1) + T(n-1,k) for k = 1,2,...,[(n+1)/2]; T(n,n/2 + 1) = T(n-1,n/2) if n is even. A26009

a(n) is the number of distinct resistances that can be obtained by a network of exactly n equal resistors, but not by any network with fewer than n equal resistors. A338197

9-gonal (or enneagonal) pyramidal numbers: a(n) = n*(n+1)*(7·n-4)/6. A7584

Least k such that there are exactly n multisets that can be obtained by choosing a divisor of each prime index of k. A355734

a(n) = n*(3·n + 4). A140676

a(1) = 8; a(n) is smallest number >= a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime. A46258

Numbers k such that lcm(1,2,3,...,k)/5 equals the denominator of the k-th harmonic number H(k). A112814

MM-numbers of labeled multigraphs with loops spanning an initial interval of positive integers. A320462