9997221 has 16 divisors (see below), whose sum is σ = 14819840. Its totient is φ = 5952960.

The previous prime is 9997219. The next prime is 9997237. The reversal of 9997221 is 1227999.

It is a happy number.

9997221 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 9997221 - 2¹ = 9997219 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 9997221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9997201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2926 + ... + 5343.

It is an arithmetic number, because the mean of its divisors is an integer number (926240).

Almost surely, 2^9997221 is an apocalyptic number.

It is an amenable number.

9997221 is a deficient number, since it is larger than the sum of its proper divisors (4822619).

9997221 is a wasteful number, since it uses less digits than its factorization.

9997221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8316.

The product of its digits is 20412, while the sum is 39.

The square root of 9997221 is about 3161.8382311560. The cubic root of 9997221 is about 215.4235099075.

The spelling of 9997221 in words is "nine million, nine hundred ninety-seven thousand, two hundred twenty-one".