21102330021 has 16 divisors (see below), whose sum is σ = 28229779200. Its totient is φ = 14021588160.

The previous prime is 21102330017. The next prime is 21102330043. The reversal of 21102330021 is 12003320112.

It is not a de Polignac number, because 21102330021 - 2² = 21102330017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102330001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4031476 + ... + 4036706.

It is an arithmetic number, because the mean of its divisors is an integer number (1764361200).

Almost surely, 2^21102330021 is an apocalyptic number.

It is an amenable number.

21102330021 is a deficient number, since it is larger than the sum of its proper divisors (7127449179).

21102330021 is a wasteful number, since it uses less digits than its factorization.

21102330021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9436.

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21102330021 its reverse (12003320112), we get a palindrome (33105650133).

Subtracting from 21102330021 its reverse (12003320112), we obtain a palindrome (9099009909).

The spelling of 21102330021 in words is "twenty-one billion, one hundred two million, three hundred thirty thousand, twenty-one".