9816705221 has 4 divisors (see below), whose sum is σ = 9834851244. Its totient is φ = 9798559200.

The previous prime is 9816705203. The next prime is 9816705229. The reversal of 9816705221 is 1225076189.

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 7856872321 + 1959832900 = 88639^2 + 44270^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9816705221 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 (9816705229) 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, 9072200 + ... + 9073281.

It is an arithmetic number, because the mean of its divisors is an integer number (2458712811).

Almost surely, 2^9816705221 is an apocalyptic number.

It is an amenable number.

9816705221 is a deficient number, since it is larger than the sum of its proper divisors (18146023).

9816705221 is a wasteful number, since it uses less digits than its factorization.

9816705221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18146022.

The product of its (nonzero) digits is 60480, while the sum is 41.

The square root of 9816705221 is about 99079.2875479028. The cubic root of 9816705221 is about 2141.1902149145.

The spelling of 9816705221 in words is "nine billion, eight hundred sixteen million, seven hundred five thousand, two hundred twenty-one".