21002100211021 has 8 divisors (see below), whose sum is σ = 21037083230720. Its totient is φ = 20967118453008.

The previous prime is 21002100211019. The next prime is 21002100211091. The reversal of 21002100211021 is 12011200120012.

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 21002100211021 - 2¹ = 21002100211019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21002100210992 and 21002100211010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002100211091) 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, 36594760 + ... + 37164238.

It is an arithmetic number, because the mean of its divisors is an integer number (2629635403840).

Almost surely, 2^{21002100211021} is an apocalyptic number.

It is an amenable number.

21002100211021 is a deficient number, since it is larger than the sum of its proper divisors (34983019699).

21002100211021 is an equidigital number, since it uses as much as digits as its factorization.

21002100211021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 630843.

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

Adding to 21002100211021 its reverse (12011200120012), we get a palindrome (33013300331033).

The spelling of 21002100211021 in words is "twenty-one trillion, two billion, one hundred million, two hundred eleven thousand, twenty-one".