21021110000221 has 8 divisors (see below), whose sum is σ = 21045985491960. Its totient is φ = 20996235318528.

The previous prime is 21021110000173. The next prime is 21021110000251. The reversal of 21021110000221 is 12200001112012.

It can be written as a sum of positive squares in 4 ways, for example, as 1364256704196 + 19656853296025 = 1168014^2 + 4433605^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21021110000221 - 2³³ = 21012520065629 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 (21021110000251) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 63576195 + ... + 63905983.

It is an arithmetic number, because the mean of its divisors is an integer number (2630748186495).

Almost surely, 2^{21021110000221} is an apocalyptic number.

It is an amenable number.

21021110000221 is a deficient number, since it is larger than the sum of its proper divisors (24875491739).

21021110000221 is an equidigital number, since it uses as much as digits as its factorization.

21021110000221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405023.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21021110000221 its reverse (12200001112012), we get a palindrome (33221111112233).

The spelling of 21021110000221 in words is "twenty-one trillion, twenty-one billion, one hundred ten million, two hundred twenty-one", and thus it is an aban number.