2623
domain: N
Properties
Digital Properties
- Digit Count
- 4
- 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
- 2728
- Proper Divisor Sum (Aliquot Sum)
- 105
- 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
- 2520
- Möbius Function
- 1
- Radical
- 2623
- 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
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 102
- Smith Number
- no
- Vampire 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
Appears in sequences
- a(n) = least integer m > a(n-1) such that m - a(n-1) != a(j) - a(k) for all j, k less than n; a(1) = 1, a(2) = 2.at n=48A004978
- Smallest number that requires n iterations of the bi-unitary totient function (A116550) to reach 1.at n=33A005424
- Expansion of 1/(1-x^3-x^4-x^5-x^6-x^7-x^8-x^9-x^10-x^11-x^12-x^13).at n=25A017826
- Numbers k such that the continued fraction for sqrt(k) has period 30.at n=42A020369
- Every suffix prime and no 0 digits in base 7 (written in base 7).at n=16A024782
- a(n) = least m such that if r and s in {1/1, 1/2, 1/3, ..., 1/n} satisfy r < s, then r < k/m < (k+4)/m < s for some integer k.at n=23A024846
- For n>0, a(n) is the least quasi-Carmichael number to base n; a(0) = least composite squarefree integer.at n=40A029590
- a(n) = Sum_{k divides 3^n} S(k), where S is the Kempner function A002034.at n=49A029714
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 11 ones.at n=3A031779
- Numbers with exactly five distinct base-7 digits.at n=28A031984
- Multiplicity of highest weight (or singular) vectors associated with character chi_8 of Monster module.at n=36A034396
- Multiplicity of highest weight (or singular) vectors associated with character chi_150 of Monster module.at n=37A034538
- a(1)=1, a(n) = smallest odd number such that all sums of pairs of (not necessarily distinct) terms in the sequence are distinct.at n=29A034757
- Coordination sequence T13 for Zeolite Code STT.at n=34A038420
- Number of partitions satisfying cn(2,5) < cn(0,5) + cn(1,5) + cn(4,5) and cn(3,5) < cn(0,5) + cn(1,5) + cn(4,5).at n=27A039873
- Numbers n such that string 3,4 occurs in the base 9 representation of n but not of n-1.at n=36A044282
- Numbers n such that string 2,3 occurs in the base 10 representation of n but not of n-1.at n=29A044355
- Numbers n such that string 7,7 occurs in the base 8 representation of n but not of n+1.at n=40A044631
- Numbers n such that string 3,4 occurs in the base 9 representation of n but not of n+1.at n=36A044663
- Numbers n such that string 2,3 occurs in the base 10 representation of n but not of n+1.at n=29A044736