21210010221 has 8 divisors (see below), whose sum is σ = 28285908640. Its totient is φ = 14137059312.

The previous prime is 21210010207. The next prime is 21210010223. The reversal of 21210010221 is 12201001212.

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

It is not a de Polignac number, because 21210010221 - 2⁵ = 21210010189 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21210010197 and 21210010206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210010223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 720031 + ... + 748908.

It is an arithmetic number, because the mean of its divisors is an integer number (3535738580).

Almost surely, 2^21210010221 is an apocalyptic number.

It is an amenable number.

21210010221 is a deficient number, since it is larger than the sum of its proper divisors (7075898419).

21210010221 is a wasteful number, since it uses less digits than its factorization.

21210010221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1473755.

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

Adding to 21210010221 its reverse (12201001212), we get a palindrome (33411011433).

Subtracting from 21210010221 its reverse (12201001212), we obtain a palindrome (9009009009).

The spelling of 21210010221 in words is "twenty-one billion, two hundred ten million, ten thousand, two hundred twenty-one".