15377
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 15378
- 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
- 15376
- Möbius Function
- -1
- Radical
- 15377
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 146
- 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
- 1797
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes of the form k^2 + 1.at n=22A002496
- Least m such that if r and s in {1/1, 1/4, 1/9,..., 1/n^2} satisfy r < s, then r < k/m < s for some integer k.at n=34A024827
- Smallest prime == 1 mod (n^2).at n=30A035091
- Numerators of continued fraction convergents to sqrt(646).at n=4A042240
- Totient(n) and cototient(n) are squares.at n=42A054754
- Odd powers of primes of the form q = x^2 + 1 (A002496).at n=31A054755
- First term of weak prime sextet: p(m+1)-p(m) < p(m+2)-p(m+1) < p(m+3)-p(m+2) < p(m+4)-p(m+3) < p(m+5)-p(m+4).at n=5A054828
- Second term of weak prime sextet: p(m)-p(m-1) < p(m+1)-p(m) < p(m+2)-p(m+1) < p(m+3)-p(m+2) < p(m+4)-p(m+3).at n=4A054829
- Second term of weak prime septet: p(m)-p(m-1) < p(m+1)-p(m) < p(m+2)-p(m+1) < p(m+3)-p(m+2) < p(m+4)-p(m+3) < p(m+5)-p(m+4).at n=0A054835
- Numbers whose divisors have the form m^k + 1, k>1.at n=24A054964
- Integers n > 1997 such that the 'Reverse and Add!' trajectory of n joins the trajectory of 1997.at n=30A063055
- Primes p such that the period of the decimal expansion of 1/p is a square.at n=24A072858
- Primes p = product(A073692(n), A073692(n)+2,..., A073692(n+1)-2) plus 2.at n=26A073691
- a(1) = 1; a(2n) is the smallest prime == 1 mod (a(2n-1)) and a(2n+1) is the smallest composite number == 1 (mod a(2n)).at n=19A075340
- a(1) = 1, a(2n) is the smallest composite number == 1 mod (a(2n-1)) and a(2n+1) is the smallest prime == 1 (mod a(2n)).at n=24A075341
- Primes p such that (p-1) and the period length of 1/p are both squares.at n=12A076516
- Primes of the form m*rad(m)+1, where rad = A007947 (squarefree kernel).at n=36A078324
- Primes p such that p-2 and p+2 are divisible by a cube.at n=2A089202
- Beginning with 3, least prime, greater than the previous term, such that the arithmetic mean of first n terms is a prime.at n=35A090918
- Triangle read by rows in which the n-th row contains the least set of n successive primes whose successive difference forms an arithmetic progression with common difference 2, (successive even numbers).at n=22A094749