21202021110021 has 16 divisors (see below), whose sum is σ = 28295643581184. Its totient is φ = 14121543443904.

The previous prime is 21202021110013. The next prime is 21202021110079. The reversal of 21202021110021 is 12001112020212.

It is not a de Polignac number, because 21202021110021 - 2³ = 21202021110013 is a prime.

It is a super-2 number, since 2×21202021110021² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21202021110091) 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, 22293591 + ... + 23225163.

It is an arithmetic number, because the mean of its divisors is an integer number (1768477723824).

Almost surely, 2^{21202021110021} is an apocalyptic number.

It is an amenable number.

21202021110021 is a deficient number, since it is larger than the sum of its proper divisors (7093622471163).

21202021110021 is a wasteful number, since it uses less digits than its factorization.

21202021110021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 938620.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21202021110021 its reverse (12001112020212), we get a palindrome (33203133130233).

The spelling of 21202021110021 in words is "twenty-one trillion, two hundred two billion, twenty-one million, one hundred ten thousand, twenty-one".