21055303 has 4 divisors (see below), whose sum is σ = 21206920. Its totient is φ = 20903688.

The previous prime is 21055301. The next prime is 21055319. The reversal of 21055303 is 30355012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21055303 - 2¹ = 21055301 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 (21055301) 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 3 ways as a sum of consecutive naturals, for example, 75600 + ... + 75877.

It is an arithmetic number, because the mean of its divisors is an integer number (5301730).

Almost surely, 2^21055303 is an apocalyptic number.

21055303 is a deficient number, since it is larger than the sum of its proper divisors (151617).

21055303 is a wasteful number, since it uses less digits than its factorization.

21055303 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151616.

The product of its (nonzero) digits is 450, while the sum is 19.

The square root of 21055303 is about 4588.6057795370. The cubic root of 21055303 is about 276.1343907231.

The spelling of 21055303 in words is "twenty-one million, fifty-five thousand, three hundred three".