20001100221 has 12 divisors (see below), whose sum is σ = 29016640380. Its totient is φ = 13275838080.

The previous prime is 20001100199. The next prime is 20001100237. The reversal of 20001100221 is 12200110002.

It can be written as a sum of positive squares in 2 ways, for example, as 14302964025 + 5698136196 = 119595^2 + 75486^2 .

It is not a de Polignac number, because 20001100221 - 2¹⁰ = 20001099197 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20001100271) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4850220 + ... + 4854341.

It is an arithmetic number, because the mean of its divisors is an integer number (2418053365).

Almost surely, 2^20001100221 is an apocalyptic number.

It is an amenable number.

20001100221 is a deficient number, since it is larger than the sum of its proper divisors (9015540159).

20001100221 is a wasteful number, since it uses less digits than its factorization.

20001100221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9704796 (or 9704793 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 20001100221 its reverse (12200110002), we get a palindrome (32201210223).

The spelling of 20001100221 in words is "twenty billion, one million, one hundred thousand, two hundred twenty-one".