21330030 has 16 divisors (see below), whose sum is σ = 51192144. Its totient is φ = 5688000.

The previous prime is 21329999. The next prime is 21330047. The reversal of 21330030 is 3003312.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21329988 and 21330015.

It is a congruent number.

It is an unprimeable number.

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, 355471 + ... + 355530.

It is an arithmetic number, because the mean of its divisors is an integer number (3199509).

Almost surely, 2^21330030 is an apocalyptic number.

21330030 is an abundant number, since it is smaller than the sum of its proper divisors (29862114).

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

21330030 is a wasteful number, since it uses less digits than its factorization.

21330030 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 711011.

The product of its (nonzero) digits is 54, while the sum is 12.

The square root of 21330030 is about 4618.4445433501. Note that the first 3 decimals coincide. The cubic root of 21330030 is about 277.3301939800.

Adding to 21330030 its reverse (3003312), we get a palindrome (24333342).

The spelling of 21330030 in words is "twenty-one million, three hundred thirty thousand, thirty".