9878221 has 4 divisors (see below), whose sum is σ = 9914944. Its totient is φ = 9841500.

The previous prime is 9878203. The next prime is 9878227. The reversal of 9878221 is 1228789.

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 3-Lehmer number, since φ(9878221) divides (9878221-1)³.

It is a cyclic number.

It is not a de Polignac number, because 9878221 - 2⁹ = 9877709 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 (9878227) 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, 17955 + ... + 18496.

It is an arithmetic number, because the mean of its divisors is an integer number (2478736).

Almost surely, 2^9878221 is an apocalyptic number.

It is an amenable number.

9878221 is a deficient number, since it is larger than the sum of its proper divisors (36723).

9878221 is a wasteful number, since it uses less digits than its factorization.

9878221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36722.

The product of its digits is 16128, while the sum is 37.

The square root of 9878221 is about 3142.9637287121. The cubic root of 9878221 is about 214.5653450553.

The spelling of 9878221 in words is "nine million, eight hundred seventy-eight thousand, two hundred twenty-one".