7649
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 7650
- 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
- 7648
- Möbius Function
- -1
- Radical
- 7649
- 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
- 114
- 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
- yes
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 971
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Where the prime race among 7k+1, ..., 7k+6 changes leader.at n=40A007354
- Numbers k such that the continued fraction for sqrt(k) has period 71.at n=4A020410
- Lower prime of a difference of 20 between consecutive primes.at n=9A031938
- Number of partitions of n into parts not of the form 21k, 21k+2 or 21k-2. Also number of partitions with 1 part of size 1 and differences between parts at distance 9 are greater than 1.at n=37A035980
- Denominators of continued fraction convergents to sqrt(254).at n=6A041477
- Denominators of continued fraction convergents to sqrt(417).at n=10A041793
- Largest prime substring in 7^n (0 if none).at n=6A046273
- McKay-Thompson series of class 14c for Monster.at n=13A058507
- Primes containing 2k digits in which the sum of the first k digits is that of the last k digits.at n=43A068896
- Define C(n) by the recursion C(0) = 2*i where i^2 = -1, C(n+1) = 1/(1 + C(n)), then a(n) = 2*(-1)^n/Im(C(n)) where Im(z) denotes the imaginary part of the complex number z.at n=9A069959
- Prime(a(n)) + ... + prime(a(n)+3) is a square = A051395(n)^2.at n=17A072849
- Primes p of the form 2*prime(k) + 3 such that 2*prime(k+1) + 3 is the next prime after p.at n=21A089528
- Sum of primes <= p is even and sum is twice a prime.at n=39A089894
- Primes that represent some mean of 4 consecutive (2 smaller, itself, 1 larger) primes.at n=19A094932
- a(n) = prime(prime(A096480(n))).at n=9A096482
- Indices of primes in sequence defined by A(0) = 97, A(n) = 10*A(n-1) - 3 for n > 0.at n=17A101013
- Primes of the form 64n+33.at n=26A105128
- Primes with digit sum = 26.at n=29A106764
- Primes p such that 3^A000027*(7*p) is a subsequence of A033631.at n=2A108510
- Primes such that the sum of the predecessor and successor primes is divisible by 29.at n=29A112859