21033403 has 8 divisors (see below), whose sum is σ = 22476960. Its totient is φ = 19612800.

The previous prime is 21033401. The next prime is 21033413. The reversal of 21033403 is 30433012.

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 21033403 - 2¹ = 21033401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21033401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3823 + ... + 7528.

It is an arithmetic number, because the mean of its divisors is an integer number (2809620).

Almost surely, 2^21033403 is an apocalyptic number.

21033403 is a deficient number, since it is larger than the sum of its proper divisors (1443557).

21033403 is a wasteful number, since it uses less digits than its factorization.

21033403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11477.

The product of its (nonzero) digits is 216, while the sum is 16.

The square root of 21033403 is about 4586.2188129220. The cubic root of 21033403 is about 276.0386200596.

Adding to 21033403 its reverse (30433012), we get a palindrome (51466415).

The spelling of 21033403 in words is "twenty-one million, thirty-three thousand, four hundred three".