Properties of the Number 1657

One Thousand Six Hundred Fifty-Seven

Basics

Value: 1656 → 1657 → 1658

Parity: odd

Prime: Yes

Previous Prime: 1637

Next Prime: 1663

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 1657

Divisors: 1, 1657

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 11001111001

Octal: 3171

Duodecimal: B61

Hexadecimal: 679

Square: 2745649

Square Root: 40.70626487409524

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

Hex (or centered hexagonal) numbers: 3·n*(n+1)+1 (crystal ball sequence for hexagonal lattice). A3215

Primes p such that 2p-1 is also prime. A5382

Primes p such that (p+1)/2 is prime. A5383

Primes whose base-2 representation is also the base-3 representation of a prime. A235266

Aitken's array: triangle of numbers {a(n,k), n >= 0, 0 <= k <= n} read by rows, defined by a(0,0)=1, a(n,0) = a(n-1,n-1), a(n,k) = a(n,k-1) + a(n-1,k-1). A11971

Primes of form n² + n + 17. A7635

Primes of the form x²+Ny², with N=102. A139643

"Three-quarter squares": a(n) = n² - A002620(n). A77043

Numbers that are the sum of 12 positive 6th powers. A3368

Primes of the form x² + 24·y². A107008