21010211221021 has 16 divisors (see below), whose sum is σ = 22981748825088. Its totient is φ = 19048986356400.

The previous prime is 21010211221009. The next prime is 21010211221031. The reversal of 21010211221021 is 12012211201012.

It is not a de Polignac number, because 21010211221021 - 2⁵ = 21010211220989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21010211220986 and 21010211221004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010211221031) 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, 5554956 + ... + 8536858.

It is an arithmetic number, because the mean of its divisors is an integer number (1436359301568).

Almost surely, 2^{21010211221021} is an apocalyptic number.

It is an amenable number.

21010211221021 is a deficient number, since it is larger than the sum of its proper divisors (1971537604067).

21010211221021 is a wasteful number, since it uses less digits than its factorization.

21010211221021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2983632.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21010211221021 its reverse (12012211201012), we get a palindrome (33022422422033).

The spelling of 21010211221021 in words is "twenty-one trillion, ten billion, two hundred eleven million, two hundred twenty-one thousand, twenty-one".