9870221 has 4 divisors (see below), whose sum is σ = 9881532. Its totient is φ = 9858912.

The previous prime is 9870199. The next prime is 9870241. The reversal of 9870221 is 1220789.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1220789 = 131 ⋅9319.

It can be written as a sum of positive squares in 2 ways, for example, as 4515625 + 5354596 = 2125^2 + 2314^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9870221 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9870241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4226 + ... + 6131.

It is an arithmetic number, because the mean of its divisors is an integer number (2470383).

Almost surely, 2^9870221 is an apocalyptic number.

It is an amenable number.

9870221 is a deficient number, since it is larger than the sum of its proper divisors (11311).

9870221 is a wasteful number, since it uses less digits than its factorization.

9870221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11310.

The product of its (nonzero) digits is 2016, while the sum is 29.

The square root of 9870221 is about 3141.6907868216. The cubic root of 9870221 is about 214.5074066083.

The spelling of 9870221 in words is "nine million, eight hundred seventy thousand, two hundred twenty-one".