21011002101021 has 4 divisors (see below), whose sum is σ = 28014669468032. Its totient is φ = 14007334734012.

The previous prime is 21011002100999. The next prime is 21011002101049. The reversal of 21011002101021 is 12010120011012.

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 not a de Polignac number, because 21011002101021 - 2⁵ = 21011002100989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21011002100988 and 21011002101006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011002101091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3501833683501 + ... + 3501833683506.

It is an arithmetic number, because the mean of its divisors is an integer number (7003667367008).

Almost surely, 2^{21011002101021} is an apocalyptic number.

It is an amenable number.

21011002101021 is a deficient number, since it is larger than the sum of its proper divisors (7003667367011).

21011002101021 is an equidigital number, since it uses as much as digits as its factorization.

21011002101021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7003667367010.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21011002101021 its reverse (12010120011012), we get a palindrome (33021122112033).

The spelling of 21011002101021 in words is "twenty-one trillion, eleven billion, two million, one hundred one thousand, twenty-one".