Properties of the Number 857

Eight Hundred Fifty-Seven

Basics

Value: 856 → 857 → 858

Parity: odd

Prime: Yes

Previous Prime: 853

Next Prime: 859

Digit Sum: 20

Digital Root: 2

Palindrome: No

Factorization: 857

Divisors: 1, 857

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 1101011001

Octal: 1531

Duodecimal: 5B5

Hexadecimal: 359

Square: 734449

Square Root: 29.274562336608895

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

Lesser of twin primes. A1359

Primes of the form 2x² + 2xy + 17y². A139827

a(n) = ∑_k=1..n k·floor(n/k); also ∑_k=1..n σ(k) where σ(n) = sum of divisors of n (A000203). A24916

Primes of form 8n+1, that is, primes congruent to 1 mod 8. A7519

Numbers n such that (22ⁿ - 1)/21 is prime. A127997

Initial members of prime triples (p, p+2, p+6). A22004

Primes of form 10n+7. A30432

Larger member p+4 of cousin primes (p, p+4). A46132

Number of steps until the RADD sequence T(k+1) = n + R(T(k)), T(0) = 1, enters a cycle; -1 if no cycle is ever reached. (R=A004086: reverse digits). A117816

Full reptend primes: primes with primitive root 10. A1913