Properties of the Number 642

Six Hundred Forty-Two

Basics

Value: 641 → 642 → 643

Parity: even

Prime: No

Previous Prime: 641

Next Prime: 643

Digit Sum: 12

Digital Root: 3

Palindrome: No

Factorization: 2 × 3 × 107

Divisors: 1, 2, 3, 6, 107, 214, 321, 642

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 1010000010

Octal: 1202

Duodecimal: 456

Hexadecimal: 282

Square: 412164

Square Root: 25.337718918639855

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

Average of twin prime pairs. A14574

Denominators of Bernoulli numbers B_2n. A2445

a(n) = 1ⁿ + 2ⁿ + 5ⁿ. A74501

Coordination sequence T1 for Zeolite Code LTA and ρ. A8137

Number of points on surface of cuboctahedron (or icosahedron): a(0) = 1; for n > 0, a(n) = 10n² + 2. Also coordination sequence for f.c.c. or A₃ or D₃ lattice. A5901

Positive integers k such that k!!! - 1 = A007661(k) - 1 is prime. A84438

Primitive abundant numbers: abundant numbers (A005101) having no abundant proper divisor. A91191

Numbers whose sum of divisors is a square. A6532

Numbers which are the sum of 3 nonzero 4th powers. A3337

Admirable numbers. A number n is admirable if there exists a proper divisor d' of n such that σ(n)-2d'=2n, where σ(n) is the sum of all divisors of n. A111592