21001000210221 has 16 divisors (see below), whose sum is σ = 28446374524160. Its totient is φ = 13779278772480.

The previous prime is 21001000210219. The next prime is 21001000210273. The reversal of 21001000210221 is 12201200010012.

It is not a de Polignac number, because 21001000210221 - 2¹ = 21001000210219 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21001000210197 and 21001000210206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001000210921) 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, 141478240 + ... + 141626601.

It is an arithmetic number, because the mean of its divisors is an integer number (1777898407760).

Almost surely, 2^{21001000210221} is an apocalyptic number.

It is an amenable number.

21001000210221 is a deficient number, since it is larger than the sum of its proper divisors (7445374313939).

21001000210221 is a wasteful number, since it uses less digits than its factorization.

21001000210221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283105236.

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

Adding to 21001000210221 its reverse (12201200010012), we get a palindrome (33202200220233).

The spelling of 21001000210221 in words is "twenty-one trillion, one billion, two hundred ten thousand, two hundred twenty-one".