21106105 has 8 divisors (see below), whose sum is σ = 25352712. Its totient is φ = 16867968.

The previous prime is 21106097. The next prime is 21106109. The reversal of 21106105 is 50160112.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 8743849 + 12362256 = 2957^2 + 3516^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21106105 - 2³ = 21106097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21106109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6757 + ... + 9373.

It is an arithmetic number, because the mean of its divisors is an integer number (3169089).

Almost surely, 2^21106105 is an apocalyptic number.

It is an amenable number.

21106105 is a deficient number, since it is larger than the sum of its proper divisors (4246607).

21106105 is a wasteful number, since it uses less digits than its factorization.

21106105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4235.

The product of its (nonzero) digits is 60, while the sum is 16.

The square root of 21106105 is about 4594.1381128564. The cubic root of 21106105 is about 276.3562970060.

Adding to 21106105 its reverse (50160112), we get a palindrome (71266217).

The spelling of 21106105 in words is "twenty-one million, one hundred six thousand, one hundred five".