21033330 has 32 divisors (see below), whose sum is σ = 50601024. Its totient is φ = 5595456.

The previous prime is 21033329. The next prime is 21033343. The reversal of 21033330 is 3333012.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an unprimeable number.

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, 22737 + ... + 23643.

It is an arithmetic number, because the mean of its divisors is an integer number (1581282).

Almost surely, 2^21033330 is an apocalyptic number.

21033330 is an abundant number, since it is smaller than the sum of its proper divisors (29567694).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21033330 is a wasteful number, since it uses less digits than its factorization.

21033330 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1690.

The product of its (nonzero) digits is 162, while the sum is 15.

The square root of 21033330 is about 4586.2108542892. The cubic root of 21033330 is about 276.0383007129.

Adding to 21033330 its reverse (3333012), we get a palindrome (24366342).

The spelling of 21033330 in words is "twenty-one million, thirty-three thousand, three hundred thirty".