9665442221 has 4 divisors (see below), whose sum is σ = 9665991744. Its totient is φ = 9664892700.

The previous prime is 9665442209. The next prime is 9665442223. The reversal of 9665442221 is 1222445669.

9665442221 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9665442221 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9665442223) 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, 247475 + ... + 283856.

It is an arithmetic number, because the mean of its divisors is an integer number (2416497936).

Almost surely, 2^9665442221 is an apocalyptic number.

It is an amenable number.

9665442221 is a deficient number, since it is larger than the sum of its proper divisors (549523).

9665442221 is a wasteful number, since it uses less digits than its factorization.

9665442221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 549522.

The product of its digits is 207360, while the sum is 41.

The square root of 9665442221 is about 98312.9809384295. The cubic root of 9665442221 is about 2130.1355627240.

The spelling of 9665442221 in words is "nine billion, six hundred sixty-five million, four hundred forty-two thousand, two hundred twenty-one".