Properties of the Number 649

Six Hundred Forty-Nine

Basics

Value: 648 → 649 → 650

Parity: odd

Prime: No

Previous Prime: 647

Next Prime: 653

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 11 × 59

Divisors: 1, 11, 59, 649

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 1010001001

Octal: 1211

Duodecimal: 461

Hexadecimal: 289

Square: 421201

Square Root: 25.475478405713993

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

a(n) = n + (n+1)². A28387

a(n) = 2·n² + 1. A58331

Number of partitions of n into pairwise relatively prime parts. A51424

Brilliant numbers: semiprimes (products of two primes, A001358) whose prime factors have the same number of decimal digits. A78972

Flavius Josephus's sieve: Start with the natural numbers; at the k-th sieving step, remove every (k+1)-st term of the sequence remaining after the (k-1)-st sieving step; iterate. A960

Numbers k such that the k-th composition in standard order is a permutation (of an initial interval). A333218

Generalized 12-gonal numbers: k*(5·k-4) for k = 0, +-1, +-2, ... A195162

Expansion of x²*(1+x-x²)/((1-x²)*(1-x)²). A24206

Numbers that are the sum of 10 positive 5th powers. A3355

Numbers whose sum of digits is 19. A166459