• 105 can be written using four 4's:

105 has 8 divisors (see below), whose sum is σ = 192. Its totient is φ = 48.

The previous prime is 103. The next prime is 107. The reversal of 105 is 501.

It is a double factorial (105 = 7 !! = 1 ⋅ 3 ⋅ 5 ⋅ 7 ).

105 is nontrivially palindromic in base 4, base 8 and base 14.

105 is an esthetic number in base 7 and base 12, because in such bases its adjacent digits differ by 1.

105 is a nontrivial binomial coefficient, being equal to C(15, 2).

It is an interprime number because it is at equal distance from previous prime (103) and next prime (107).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 105 - 2^{1} = 103 is a prime.

It is a super-2 number, since 2×105^{2} = 22050, which contains 22 as substring.

105 is an idoneal number.

It is an alternating number because its digits alternate between odd and even.

105 is an undulating number in base 8.

It is a Curzon number.

105 is a lucky number.

105 is a nontrivial repdigit in base 14.

It is a plaindrome in base 9, base 12, base 14 and base 16.

It is a nialpdrome in base 5, base 7, base 11, base 13, base 14 and base 15.

It is a zygodrome in base 14.

It is a junction number, because it is equal to *n*+sod(*n*) for *n* = 93 and 102.

It is a Zeisel number, with parameters (1, 2).

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12 + ... + 18.

It is an arithmetic number, because the mean of its divisors is an integer number (24).

105 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

105 is the 14-th triangular number.

It is an amenable number.

105 is a deficient number, since it is larger than the sum of its proper divisors (87).

105 is an equidigital number, since it uses as much as digits as its factorization.

With its predecessor (104) it forms a Ruth-Aaron pair, since the sum of their distinct prime factors is the same (15).

105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15.

The product of its (nonzero) digits is 5, while the sum is 6.

The square root of 105 is about 10.2469507660. The cubic root of 105 is about 4.7176939803.

Adding to 105 its reverse (501), we get a palindrome (606).

It can be divided in two parts, 10 and 5, that added together give a triangular number (15 = T_{5}).

The spelling of 105 in words is "one hundred five", and thus it is an aban number.

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