21066315 has 16 divisors (see below), whose sum is σ = 35689248. Its totient is φ = 10574336.

The previous prime is 21066299. The next prime is 21066319. The reversal of 21066315 is 51366012.

It is a cyclic number.

It is not a de Polignac number, because 21066315 - 2⁴ = 21066299 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21066319) 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 15 ways as a sum of consecutive naturals, for example, 41052 + ... + 41561.

It is an arithmetic number, because the mean of its divisors is an integer number (2230578).

Almost surely, 2^21066315 is an apocalyptic number.

21066315 is a deficient number, since it is larger than the sum of its proper divisors (14622933).

21066315 is a wasteful number, since it uses less digits than its factorization.

21066315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82638.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 21066315 is about 4589.8055514368. The cubic root of 21066315 is about 276.1825220965.

The spelling of 21066315 in words is "twenty-one million, sixty-six thousand, three hundred fifteen".