9810221210221 has 4 divisors (see below), whose sum is σ = 9810412266844. Its totient is φ = 9810030153600.

The previous prime is 9810221210197. The next prime is 9810221210263. The reversal of 9810221210221 is 1220121220189.

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 4738654154025 + 5071567056196 = 2176845^2 + 2252014^2 .

It is a cyclic number.

It is not a de Polignac number, because 9810221210221 - 2⁵ = 9810221210189 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 (9810221210281) 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, 95451270 + ... + 95553991.

It is an arithmetic number, because the mean of its divisors is an integer number (2452603066711).

Almost surely, 2^{9810221210221} is an apocalyptic number.

It is an amenable number.

9810221210221 is a deficient number, since it is larger than the sum of its proper divisors (191056623).

9810221210221 is a wasteful number, since it uses less digits than its factorization.

9810221210221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191056622.

The product of its (nonzero) digits is 2304, while the sum is 31.

The spelling of 9810221210221 in words is "nine trillion, eight hundred ten billion, two hundred twenty-one million, two hundred ten thousand, two hundred twenty-one".