7920909 has 10 divisors (see below), whose sum is σ = 11832590. Its totient is φ = 5280552.

The previous prime is 7920893. The next prime is 7920949. The reversal of 7920909 is 9090297.

It can be written as a sum of positive squares in only one way, i.e., 6812100 + 1108809 = 2610^2 + 1053^2 .

It is not a de Polignac number, because 7920909 - 2⁴ = 7920893 is a prime.

It is a Duffinian number.

7920909 is a modest number, since divided by 909 gives 792 as remainder.

7920909 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7920949) 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 9 ways as a sum of consecutive naturals, for example, 48814 + ... + 48975.

It is an arithmetic number, because the mean of its divisors is an integer number (1183259).

Almost surely, 2^7920909 is an apocalyptic number.

It is an amenable number.

7920909 is a deficient number, since it is larger than the sum of its proper divisors (3911681).

7920909 is an equidigital number, since it uses as much as digits as its factorization.

7920909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97801 (or 97792 counting only the distinct ones).

The product of its (nonzero) digits is 10206, while the sum is 36.

The square root of 7920909 is about 2814.4109508030. The cubic root of 7920909 is about 199.3387243154.

The spelling of 7920909 in words is "seven million, nine hundred twenty thousand, nine hundred nine".