21100011000221 has 4 divisors (see below), whose sum is σ = 21131363171772. Its totient is φ = 21068658828672.

The previous prime is 21100011000217. The next prime is 21100011000227. The reversal of 21100011000221 is 12200011000112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15495835425625 + 5604175574596 = 3936475^2 + 2367314^2 .

It is a cyclic number.

It is not a de Polignac number, because 21100011000221 - 2² = 21100011000217 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100011000227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15676084766 + ... + 15676086111.

It is an arithmetic number, because the mean of its divisors is an integer number (5282840792943).

Almost surely, 2^{21100011000221} is an apocalyptic number.

It is an amenable number.

21100011000221 is a deficient number, since it is larger than the sum of its proper divisors (31352171551).

21100011000221 is an equidigital number, since it uses as much as digits as its factorization.

21100011000221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31352171550.

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

Adding to 21100011000221 its reverse (12200011000112), we get a palindrome (33300022000333).

The spelling of 21100011000221 in words is "twenty-one trillion, one hundred billion, eleven million, two hundred twenty-one", and thus it is an aban number.