9929
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 29
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 9930
- Proper Divisor Sum (Aliquot Sum)
- 1
- 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
- 9928
- Möbius Function
- -1
- Radical
- 9929
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 135
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1224
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers k where |cos(k)| (or |cosec(k)| or |cot(k)|) decreases monotonically to 0; also numbers k where |tan(k)| (or |sec(k)|, or |sin(k)|) increases.at n=33A004112
- Supersingular primes of the elliptic curve X_0 (11).at n=15A006962
- Numbers k such that the continued fraction for sqrt(k) has period 83.at n=4A020422
- Primes that contain digits 2 and 9 only.at n=5A020460
- Least k such that tan(k) > tan(a(n-1)), for n >= 1, where a(0) = 0.at n=44A024814
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 44 ones.at n=38A031812
- Numbers having three 9's in base 10.at n=20A043527
- Numbers k where cos(k) decreases monotonically to 0.at n=17A046957
- Numbers k where sin(k) increases monotonically to 1 (or cosec(k) decreases).at n=21A046959
- Primes p for which the period of reciprocal = (p-1)/8.at n=20A056213
- Expansion of (1-x^2)/(1-3*x-x^2+x^3).at n=8A061534
- Primes starting and ending with 9.at n=27A062335
- Numbers k such that floor(tan(k)) > floor(tan(m)) for all m < k.at n=41A063537
- Numbers k such that sigma(k+2) - sigma(k) = prime(k+1) - prime(k).at n=29A067062
- Number of distinct primes in the numerator of the 2^n sums generated from the set 1, 1/2, 1/3, ..., 1/n.at n=16A075189
- a(n) = largest prime using least number of possible digits with a digit sum n, or 0 if no such number exists. E.g., if n > 9 and there are no two-digit primes with a given digit sum n then three-digit numbers are explored and so on.at n=28A088115
- Number of configurations of the sliding block 8-puzzle that require a minimum of n moves to be reached, starting with the empty square at mid-side.at n=26A089483
- The sixth column of triangle A091492, excluding leading zeros.at n=48A091498
- Lesser of the greatest twin prime pair with n digits.at n=3A092250
- Sophie Germain type primes where 7*Prime[n]=2*Prime[m]+1.at n=41A104165