Properties of the Number 648

Six Hundred Forty-Eight

Basics

Value: 647 → 648 → 649

Parity: even

Prime: No

Previous Prime: 647

Next Prime: 653

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 2 ³ × 3 ⁴

Divisors: 1, 2, 3, 4, 6, 8, 9, 12, 18, 24

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 1010001000

Octal: 1210

Duodecimal: 460

Hexadecimal: 288

Square: 419904

Square Root: 25.45584412271571

Classification

Fibonacci: No

Bell Number: No

Factorial Number: No

Regular Number: Yes

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

Powerful numbers, definition (1): if a prime p divides n then p² must also divide n (also called squareful, square full, square-full or 2-powerful numbers). A1694

3-smooth numbers: numbers of the form 2ⁱ*3^j with i, j >= 0. A3586

Numbers all of whose prime divisors are consecutive primes starting at 2. A55932

a(n) = 2·n². A1105

Squares and twice squares. A28982

Powerful numbers (A001694) that are not prime powers (A000961). A286708

3-full (or cube-full, or cubefull) numbers: if a prime p divides n then so does p³. A36966

a(n) = ceiling(n²/2). A982

Jordan function J₂(n) (a generalization of φ(n)). A7434

Triangle read by rows: T(n,m) (n >= m >= 1) = number of regions (or cells) formed by drawing the line segments connecting any two of the 2*(m+n) perimeter points of an m X n grid of squares. A331452