21033110021 has 64 divisors (see below), whose sum is σ = 27547361280. Its totient is φ = 15586421760.

The previous prime is 21033110011. The next prime is 21033110023. The reversal of 21033110021 is 12001133012.

It is not a de Polignac number, because 21033110021 - 2¹⁴ = 21033093637 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21033109978 and 21033110005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21033110023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 25432610 + ... + 25433436.

It is an arithmetic number, because the mean of its divisors is an integer number (430427520).

Almost surely, 2^21033110021 is an apocalyptic number.

It is an amenable number.

21033110021 is a deficient number, since it is larger than the sum of its proper divisors (6514251259).

21033110021 is a wasteful number, since it uses less digits than its factorization.

21033110021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1074.

The product of its (nonzero) digits is 36, while the sum is 14.

Adding to 21033110021 its reverse (12001133012), we get a palindrome (33034243033).

The spelling of 21033110021 in words is "twenty-one billion, thirty-three million, one hundred ten thousand, twenty-one".