21020010011021 has 16 divisors (see below), whose sum is σ = 24472971158400. Its totient is φ = 17680647890688.

The previous prime is 21020010010943. The next prime is 21020010011047. The reversal of 21020010011021 is 12011001002012.

It is a cyclic number.

It is not a de Polignac number, because 21020010011021 - 2¹⁰ = 21020010009997 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21020010010993 and 21020010011011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020010011051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 44489000 + ... + 44958993.

It is an arithmetic number, because the mean of its divisors is an integer number (1529560697400).

Almost surely, 2^{21020010011021} is an apocalyptic number.

It is an amenable number.

21020010011021 is a deficient number, since it is larger than the sum of its proper divisors (3452961147379).

21020010011021 is an equidigital number, since it uses as much as digits as its factorization.

21020010011021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89448628.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21020010011021 its reverse (12011001002012), we get a palindrome (33031011013033).

Subtracting from 21020010011021 its reverse (12011001002012), we obtain a palindrome (9009009009009).

The spelling of 21020010011021 in words is "twenty-one trillion, twenty billion, ten million, eleven thousand, twenty-one".