21107005 has 16 divisors (see below), whose sum is σ = 27316800. Its totient is φ = 15603840.

The previous prime is 21106997. The next prime is 21107017. The reversal of 21107005 is 50070112.

It is not a de Polignac number, because 21107005 - 2³ = 21106997 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21107005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1186 + ... + 6604.

It is an arithmetic number, because the mean of its divisors is an integer number (1707300).

Almost surely, 2^21107005 is an apocalyptic number.

It is an amenable number.

21107005 is a deficient number, since it is larger than the sum of its proper divisors (6209795).

21107005 is a wasteful number, since it uses less digits than its factorization.

21107005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5484.

The product of its (nonzero) digits is 70, while the sum is 16.

The square root of 21107005 is about 4594.2360627203. The cubic root of 21107005 is about 276.3602250501.

Adding to 21107005 its reverse (50070112), we get a palindrome (71177117).

The spelling of 21107005 in words is "twenty-one million, one hundred seven thousand, five".