11215
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 10
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 13464
- Proper Divisor Sum (Aliquot Sum)
- 2249
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8968
- Möbius Function
- 1
- Radical
- 11215
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 68
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- 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
- no
- Odd
- yes
Appears in sequences
- Number of partitions of 1/n into 4 reciprocals of positive integers.at n=13A020327
- Positive numbers for which the sum of digits equals the product of digits.at n=31A034710
- Product of the digits of n divides the sum of the digits of n.at n=47A055931
- McKay-Thompson series of class 28a for Monster.at n=31A058610
- Coefficients in expansion of Sum_{n >= 1} x^n/(1-x^n)^4.at n=38A059358
- Numbers whose product of decimal digits equals its sum of binary digits.at n=18A064003
- Integers m such that (x1*x2*..xk)^(x1+x2+..xk) = (x1+x2+..xk)^(x1*x2*..xk) where x1x2..xk are the digits of m in base 10.at n=34A064158
- Nonprimes whose sum of digits is equal to its product of digits.at n=24A066307
- Triangle, read by rows, where T(0,0) = 1, T(n,k) = (-1)^n*(2n+1)*T(n-1,k) - T(n-1,k-1).at n=23A108083
- Semiprimes for which both the sum and the product of the digits is also a semiprime.at n=30A118690
- Number of distinct means of nonempty subsets of {1,...,n}.at n=47A135342
- Numbers k such that k and k^2 use only the digits 1, 2, 5, 6 and 7.at n=33A137004
- Numbers k such that (sum of base-2 digits of k) = (sum of base-10 digits of k) = 10.at n=11A152207
- Numbers n such that d(1)^1 + d(2)^2 + ... + d(p)^p and d(1)^p + d(2)^p-1 +... + d(p)^1 are squares, where d(i), i=1..p, are the digits of n.at n=29A178360
- Numbers with digital product = 10.at n=22A199990
- Composite numbers whose product of digits is 10.at n=20A201057
- G.f.: A(x) = Sum_{n>=0} x^n / (1 - x^n - x^(2*n))^n.at n=21A223547
- Composite numbers for which the root mean square of proper divisors is an integer.at n=21A247135
- The curvature (rounded down) of touching circles inscribed in a special way in the smaller segment of circle of radius 10/9 divided by a chord of length 4/3.at n=13A247512
- Numbers k such that k + (sum of digits of k) and k + (product of digits of k) contain the same distinct digits of k.at n=4A248718