21084605 has 8 divisors (see below), whose sum is σ = 25331712. Its totient is φ = 16847568.

The previous prime is 21084601. The next prime is 21084611. The reversal of 21084605 is 50648012.

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 21084605 - 2² = 21084601 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21084601) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3332 + ... + 7298.

It is an arithmetic number, because the mean of its divisors is an integer number (3166464).

Almost surely, 2^21084605 is an apocalyptic number.

It is an amenable number.

21084605 is a deficient number, since it is larger than the sum of its proper divisors (4247107).

21084605 is a wasteful number, since it uses less digits than its factorization.

21084605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5035.

The product of its (nonzero) digits is 1920, while the sum is 26.

The square root of 21084605 is about 4591.7975782911. The cubic root of 21084605 is about 276.2624271827.

The spelling of 21084605 in words is "twenty-one million, eighty-four thousand, six hundred five".