17623
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 17624
- Proper Divisor Sum (Aliquot Sum)
- 1
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 17622
- Möbius Function
- -1
- Radical
- 17623
- 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
- 53
- 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
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 2026
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Convolution of natural numbers n >= 1 with Fibonacci numbers F(k), k >= 4.at n=14A033960
- Smallest prime in n-th shell of prime spiral.at n=23A053998
- Primes p whose period of reciprocal equals (p-1)/9.at n=12A056214
- Primes which are the concatenation of numbers n_1, n_2, n_3, in that order, with n_1 + n_2 = n_3 (leading zeros are forbidden for nonzero n_i).at n=28A067860
- a(n) = 2*a(n-1)^2 - a(n-2)^2 with a(0)=0, a(1)=1.at n=5A076740
- Record-setting differences between adjacent elements of the Mian-Chowla sequence variant A058335.at n=42A080931
- Primes in which the digit string can be partitioned into three parts such that the sum of the first two is equal to the third, and the second part is nonzero.at n=27A088291
- Duplicate of A056214.at n=12A098676
- Largest prime of the set of four consecutive primes whose sum of digits is a set of four distinct primes.at n=33A106818
- a(n) is n-th prime == 1 (mod 6n).at n=32A138906
- Primes congruent to 27 mod 53.at n=36A142557
- Primes congruent to 41 mod 59.at n=29A142768
- Primes congruent to 55 mod 61.at n=34A142853
- Primes p such that p^2 - 2 is a 5-almost prime.at n=27A156620
- Noncomposite numbers in the southern ray of the Ulam spiral as oriented on the March 1964 cover of Scientific American.at n=17A168027
- Number of 8-line partitions of n (i.e., planar partitions of n with at most 8 lines).at n=17A225198
- a(n) = the frequency of the most common final digit of a prime with n digits.at n=5A244253
- Primes of the form p==3 (mod 4) such that the average of their primitive roots equals p/2.at n=12A267010
- Primes p such that there are exactly p solutions to y^2 + x*y + y == x^3 + x^2 - 10*x - 10 (mod p).at n=25A275777
- a(1) = 2; a(n + 1) = smallest prime > a(n) such that a(n + 1) - a(n) is the product of 7 primes.at n=27A285692