21102000121021 has 8 divisors (see below), whose sum is σ = 21617049505464. Its totient is φ = 20586968186880.

The previous prime is 21102000121019. The next prime is 21102000121051. The reversal of 21102000121021 is 12012100020112.

It can be written as a sum of positive squares in 4 ways, for example, as 67944156921 + 21034055964100 = 260661^2 + 4586290^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21102000121021 - 2¹ = 21102000121019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21102000120992 and 21102000121010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102000121051) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1897746 + ... + 6767971.

It is an arithmetic number, because the mean of its divisors is an integer number (2702131188183).

Almost surely, 2^{21102000121021} is an apocalyptic number.

It is an amenable number.

21102000121021 is a deficient number, since it is larger than the sum of its proper divisors (515049384443).

21102000121021 is an equidigital number, since it uses as much as digits as its factorization.

21102000121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8725151.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21102000121021 its reverse (12012100020112), we get a palindrome (33114100141133).

The spelling of 21102000121021 in words is "twenty-one trillion, one hundred two billion, one hundred twenty-one thousand, twenty-one".