21001100020221 has 16 divisors (see below), whose sum is σ = 29219202625536. Its totient is φ = 13391877083376.

The previous prime is 21001100020217. The next prime is 21001100020249. The reversal of 21001100020221 is 12202000110012.

It is not a de Polignac number, because 21001100020221 - 2² = 21001100020217 is a prime.

It is a super-3 number, since 3×21001100020221³ (a number of 41 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21001100020197 and 21001100020206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001100020721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6044796 + ... + 8862378.

It is an arithmetic number, because the mean of its divisors is an integer number (1826200164096).

Almost surely, 2^{21001100020221} is an apocalyptic number.

It is an amenable number.

21001100020221 is a deficient number, since it is larger than the sum of its proper divisors (8218102605315).

21001100020221 is a wasteful number, since it uses less digits than its factorization.

21001100020221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2925632.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21001100020221 its reverse (12202000110012), we get a palindrome (33203100130233).

The spelling of 21001100020221 in words is "twenty-one trillion, one billion, one hundred million, twenty thousand, two hundred twenty-one".