21033330021 has 40 divisors (see below), whose sum is σ = 34857583200. Its totient is φ = 12531382560.

The previous prime is 21033330013. The next prime is 21033330041. The reversal of 21033330021 is 12003333012.

21033330021 is a `hidden beast` number, since 2 + 10 + 333 + 300 + 21 = 666.

It is not a de Polignac number, because 21033330021 - 2³ = 21033330013 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21033329976 and 21033330003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21033330041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 147486 + ... + 252623.

It is an arithmetic number, because the mean of its divisors is an integer number (871439580).

Almost surely, 2^21033330021 is an apocalyptic number.

It is an amenable number.

21033330021 is a deficient number, since it is larger than the sum of its proper divisors (13824253179).

21033330021 is a wasteful number, since it uses less digits than its factorization.

21033330021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 400191 (or 400182 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 18.

Adding to 21033330021 its reverse (12003333012), we get a palindrome (33036663033).

The spelling of 21033330021 in words is "twenty-one billion, thirty-three million, three hundred thirty thousand, twenty-one".