21055306 has 8 divisors (see below), whose sum is σ = 33245280. Its totient is φ = 9973548.

The previous prime is 21055301. The next prime is 21055319. The reversal of 21055306 is 60355012.

It is a happy number.

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

It is not an unprimeable number, because it can be changed into a prime (21055301) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 277006 + ... + 277081.

It is an arithmetic number, because the mean of its divisors is an integer number (4155660).

Almost surely, 2^21055306 is an apocalyptic number.

21055306 is a deficient number, since it is larger than the sum of its proper divisors (12189974).

21055306 is a wasteful number, since it uses less digits than its factorization.

21055306 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 554108.

The product of its (nonzero) digits is 900, while the sum is 22.

The square root of 21055306 is about 4588.6061064336. The cubic root of 21055306 is about 276.1344038378.

The spelling of 21055306 in words is "twenty-one million, fifty-five thousand, three hundred six".