7621
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 7622
- 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
- 7620
- Möbius Function
- -1
- Radical
- 7621
- 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
- 39
- 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
- 968
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Number of n-input 2-output switching networks under action of AG(n,2) on the inputs and complementing group C(2,2) on the outputs.at n=3A000850
- Primes that remain prime through 3 iterations of function f(x) = 5x + 8.at n=17A023286
- Primes that remain prime through 4 iterations of function f(x) = 5x + 8.at n=5A023316
- Primes that remain prime through 5 iterations of function f(x) = 5x + 8.at n=1A023344
- Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 11.at n=8A031599
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 48 ones.at n=21A031816
- Upper prime of a difference of 14 between consecutive primes.at n=38A031933
- Lower prime of a difference of 18 between consecutive primes.at n=32A031936
- Primes with distinct digits in descending order.at n=36A052014
- Sum of the first n Sophie Germain primes.at n=29A066819
- Largest prime factor of 5^n + 1.at n=15A074478
- Largest prime factor of 5^n - 1.at n=29A074479
- Primes p such that sum of even digits of p equals sum of odd digits of p.at n=32A076167
- Prime numbers in which the sum of the external digits = the sum of the internal digits.at n=41A088290
- Primes p such that (p-11)/10 is also a prime.at n=33A089442
- a(n) = r-th prime of the form (p-q)/(q-r) with r=prime(n+1), q=prime(n+2), and primes p > q.at n=53A089577
- a(n) is the least positive integer such that the integer part of the arithmetic-geometric mean of a(n) and 2^n is equal to 3^n.at n=7A090857
- Beginning with 2, least prime not occurring earlier such that the concatenation of first n terms has the least prime factor prime(n).at n=45A100759
- Primes from merging of 4 successive digits in decimal expansion of the Golden Ratio, (1+sqrt(5))/2.at n=38A103810
- Numbers k such that 13k = 6j^2 + 6j + 1.at n=19A106390