2640509 has 2 divisors, whose sum is σ = 2640510. Its totient is φ = 2640508.

The previous prime is 2640503. The next prime is 2640511. The reversal of 2640509 is 9050462.

2640509 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1951609 + 688900 = 1397^2 + 830^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2640509 is a prime.

It is a Sophie Germain prime.

Together with 2640511, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2640503) 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 as a sum of consecutive naturals, namely, 1320254 + 1320255.

It is an arithmetic number, because the mean of its divisors is an integer number (1320255).

2^2640509 is an apocalyptic number.

It is an amenable number.

2640509 is a deficient number, since it is larger than the sum of its proper divisors (1).

2640509 is an equidigital number, since it uses as much as digits as its factorization.

2640509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 2640509 is about 1624.9643073003. The cubic root of 2640509 is about 138.2173463664.

The spelling of 2640509 in words is "two million, six hundred forty thousand, five hundred nine".