7640909 has 2 divisors, whose sum is σ = 7640910. Its totient is φ = 7640908.

The previous prime is 7640903. The next prime is 7640929. The reversal of 7640909 is 9090467.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7171684 + 469225 = 2678^2 + 685^2 .

It is a cyclic number.

It is not a de Polignac number, because 7640909 - 2¹² = 7636813 is a prime.

7640909 is a modest number, since divided by 909 gives 764 as remainder.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7640903) 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 as a sum of consecutive naturals, namely, 3820454 + 3820455.

It is an arithmetic number, because the mean of its divisors is an integer number (3820455).

Almost surely, 2^7640909 is an apocalyptic number.

It is an amenable number.

7640909 is a deficient number, since it is larger than the sum of its proper divisors (1).

7640909 is an equidigital number, since it uses as much as digits as its factorization.

7640909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 7640909 is about 2764.2194196554. The cubic root of 7640909 is about 196.9616509135.

The spelling of 7640909 in words is "seven million, six hundred forty thousand, nine hundred nine".