21002100002121 has 8 divisors (see below), whose sum is σ = 32003200003264. Its totient is φ = 12001200001200.

The previous prime is 21002100002087. The next prime is 21002100002201. The reversal of 21002100002121 is 12120000120012.

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

It is not a de Polignac number, because 21002100002121 - 2¹⁰ = 21002100001097 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21002100002097 and 21002100002106.

It is not an unprimeable number, because it can be changed into a prime (21002100002921) 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, 500050000030 + ... + 500050000071.

It is an arithmetic number, because the mean of its divisors is an integer number (4000400000408).

Almost surely, 2^{21002100002121} is an apocalyptic number.

21002100002121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21002100002121 is a deficient number, since it is larger than the sum of its proper divisors (11001100001143).

21002100002121 is a wasteful number, since it uses less digits than its factorization.

21002100002121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1000100000111.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21002100002121 its reverse (12120000120012), we get a palindrome (33122100122133).

The spelling of 21002100002121 in words is "twenty-one trillion, two billion, one hundred million, two thousand, one hundred twenty-one".