3950
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 7440
- Proper Divisor Sum (Aliquot Sum)
- 3490
- 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
- 1560
- Möbius Function
- 0
- Radical
- 790
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 3
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
- 38
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- Number of partitions of n, with two kinds of 1, 2, 3 and 4.at n=16A000710
- Coordination sequence T6 for Zeolite Code MTT.at n=39A008194
- Coordination sequence T6 for Zeolite Code MTT.at n=38A008194
- Coordination sequence T2 for Milarite.at n=39A008257
- Triangle read by rows: T(n,k) is one-half the number of permutations of length n with exactly n-k rising or falling successions, for n >= 1, 1 <= k <= n. T(1,1) = 1 by convention.at n=48A010028
- Convolution of natural numbers >= 2 and natural numbers >= 3.at n=24A023545
- Coordination sequence T4 for Zeolite Code IFR.at n=44A024985
- a(n) = T(2n-1,n) + T(2n,n+1) + ... + T(3n-3,2n-2) = sum over a period of n-th diagonal of array T given by A049828.at n=47A049833
- McKay-Thompson series of class 18b for the Monster group.at n=15A058537
- McKay-Thompson series of class 32B for the Monster group.at n=30A058630
- Numbers k such that 3*2^k + 7 is prime.at n=25A059746
- Records in the Conway's alimentary function A070871.at n=37A070926
- Numbers n such that Rd(n) + Ld(n) +/-1 is prime, where Rd and Ld are the right- and left-digital factorial functions.at n=44A071714
- Last digit of n, phi(n) and sigma(n) is 0 in base 10.at n=27A072604
- Numbers k such that A000010(k) divides A074639(k).at n=36A074645
- Expansion of 1/(1+x+2*x^2-x^3).at n=19A077978
- Triangle read by rows: T(n,k) = one-half number of permutations of length n with exactly k rising or falling successions, for n >= 1, 0 <= k <= n-1. T(1,0) = 1 by convention.at n=51A086856
- Numbers k such that sigma(phi(k))-phi(sigma(k)) is nonzero and divisible by phi(k), that is A065395(k)/A000010(k) is a nonzero integer.at n=29A092587
- a(1)=0, and a(n+1) is the position of first occurrence of a(n) in the decimal expansion of 1/Pi.at n=20A098319
- a(1) = 1; a(n) = sum of previous terms a(k) such that a(k) + n is prime.at n=50A108867