21064305 has 8 divisors (see below), whose sum is σ = 33702912. Its totient is φ = 11234288.

The previous prime is 21064301. The next prime is 21064313. The reversal of 21064305 is 50346012.

It is a happy number.

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 21064305 - 2² = 21064301 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21064301) 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, 702129 + ... + 702158.

It is an arithmetic number, because the mean of its divisors is an integer number (4212864).

Almost surely, 2^21064305 is an apocalyptic number.

It is an amenable number.

21064305 is a deficient number, since it is larger than the sum of its proper divisors (12638607).

21064305 is a wasteful number, since it uses less digits than its factorization.

21064305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1404295.

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 21064305 is about 4589.5865826891. The cubic root of 21064305 is about 276.1737380175.

The spelling of 21064305 in words is "twenty-one million, sixty-four thousand, three hundred five".