247
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 280
- Proper Divisor Sum (Aliquot Sum)
- 33
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 216
- Möbius Function
- 1
- Radical
- 247
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- yes
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 47
- Smith Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Names
- German
- zweihundertsiebenundvierzig· ordinal: zweihundertsiebenundvierzigste
- English
- two hundred forty-seven· ordinal: two hundred forty-seventh
- Spanish
- doscientos cuarenta y siete· ordinal: 247º
- French
- deux cent quarante-sept· ordinal: deux cent quarante-septième
- Italian
- duecentoquarantasette· ordinal: 247º
- Latin
- ducenti quadraginta septem· ordinal: 247.
- Portuguese
- duzentos e quarenta e sete· ordinal: 247º
Appears in sequences
- Eulerian numbers (Euler's triangle: column k=2 of A008292, column k=1 of A173018).at n=8A000295
- Pentagonal numbers: a(n) = n*(3*n-1)/2.at n=13A000326
- Numbers that are not the sum of 4 tetrahedral numbers.at n=16A000797
- Number of free planar polyenoids with n nodes and symmetry point group C_{2v}.at n=13A000936
- n! never ends in this many 0's.at n=47A000966
- Expansion of g.f. (1 + x + 2*x^2)/((1 - x)^2*(1 - x^3)).at n=18A000969
- Moran numbers: k such that k/(sum of digits of k) is prime.at n=23A001101
- Number of partitions of n into squares.at n=66A001156
- Eulerian numbers (Euler's triangle: column k=7 of A008292, column k=6 of A173018).at n=1A001243
- Generalized pentagonal numbers: m*(3*m - 1)/2, m = 0, +-1, +-2, +-3, ....at n=25A001318
- The coding-theoretic function A(n,4,3).at n=38A001839
- Expansion of g.f. x/((1 - x)^2*(1 - x^3)).at n=37A001840
- v-pile positions of the 4-Wythoff game with i=1.at n=47A001964
- Number of two-rowed partitions of length 3.at n=14A001993
- Numbers dividing A002037(i) and larger than A002037(i-1), for some i>0.at n=19A002038
- Odd squarefree numbers with an even number of prime factors that have no prime factors greater than 31.at n=29A002557
- Numbers k such that (k^2 + k + 1)/21 is prime.at n=13A002644
- a(n) = 2*sigma(n) - 1.at n=47A002659
- Numbers k such that (k^2 + 1)/10 is prime.at n=24A002733
- a(n) = n + Sum_{k=1..n} pi(k), where pi() = A000720.at n=33A002815