9170721 has 24 divisors (see below), whose sum is σ = 15799680. Its totient is φ = 5011776.

The previous prime is 9170717. The next prime is 9170723. The reversal of 9170721 is 1270719.

It is not a de Polignac number, because 9170721 - 2² = 9170717 is a prime.

9170721 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (9170723) 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 23 ways as a sum of consecutive naturals, for example, 1716 + ... + 4613.

It is an arithmetic number, because the mean of its divisors is an integer number (658320).

Almost surely, 2^9170721 is an apocalyptic number.

It is an amenable number.

9170721 is a deficient number, since it is larger than the sum of its proper divisors (6628959).

9170721 is a wasteful number, since it uses less digits than its factorization.

9170721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6365 (or 6362 counting only the distinct ones).

The product of its (nonzero) digits is 882, while the sum is 27.

The square root of 9170721 is about 3028.3198311935. The cubic root of 9170721 is about 209.3153896092.

The spelling of 9170721 in words is "nine million, one hundred seventy thousand, seven hundred twenty-one".