7109721 has 8 divisors (see below), whose sum is σ = 10532960. Its totient is φ = 4739796.

The previous prime is 7109681. The next prime is 7109731. The reversal of 7109721 is 1279017.

It is not a de Polignac number, because 7109721 - 2⁹ = 7109209 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 263323 = 7109721 / (7 + 1 + 0 + 9 + 7 + 2 + 1).

It is a Duffinian number.

7109721 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (7109731) 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 7 ways as a sum of consecutive naturals, for example, 131635 + ... + 131688.

It is an arithmetic number, because the mean of its divisors is an integer number (1316620).

Almost surely, 2^7109721 is an apocalyptic number.

It is an amenable number.

7109721 is a deficient number, since it is larger than the sum of its proper divisors (3423239).

7109721 is a wasteful number, since it uses less digits than its factorization.

7109721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263332 (or 263326 counting only the distinct ones).

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

The square root of 7109721 is about 2666.4060080940. The cubic root of 7109721 is about 192.2874113464.

The spelling of 7109721 in words is "seven million, one hundred nine thousand, seven hundred twenty-one".