21002110102021 has 4 divisors (see below), whose sum is σ = 21915245323872. Its totient is φ = 20088974880172.

The previous prime is 21002110101983. The next prime is 21002110102087. The reversal of 21002110102021 is 12020101120012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21002110102021 - 2¹³ = 21002110093829 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21002110101992 and 21002110102010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002110102121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 456567610891 + ... + 456567610936.

It is an arithmetic number, because the mean of its divisors is an integer number (5478811330968).

Almost surely, 2^{21002110102021} is an apocalyptic number.

It is an amenable number.

21002110102021 is a deficient number, since it is larger than the sum of its proper divisors (913135221851).

21002110102021 is an equidigital number, since it uses as much as digits as its factorization.

21002110102021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 913135221850.

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

Adding to 21002110102021 its reverse (12020101120012), we get a palindrome (33022211222033).

The spelling of 21002110102021 in words is "twenty-one trillion, two billion, one hundred ten million, one hundred two thousand, twenty-one".