2656509 has 4 divisors (see below), whose sum is σ = 3542016. Its totient is φ = 1771004.

The previous prime is 2656501. The next prime is 2656529. The reversal of 2656509 is 9056562.

2656509 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2656509 - 2³ = 2656501 is a prime.

It is a D-number.

It is a self number, because there is not a number n which added to its sum of digits gives 2656509.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2656501) 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 in 3 ways as a sum of consecutive naturals, for example, 442749 + ... + 442754.

It is an arithmetic number, because the mean of its divisors is an integer number (885504).

2^2656509 is an apocalyptic number.

It is an amenable number.

2656509 is a deficient number, since it is larger than the sum of its proper divisors (885507).

2656509 is an equidigital number, since it uses as much as digits as its factorization.

2656509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 885506.

The product of its (nonzero) digits is 16200, while the sum is 33.

The square root of 2656509 is about 1629.8800569367. The cubic root of 2656509 is about 138.4959575165.

The spelling of 2656509 in words is "two million, six hundred fifty-six thousand, five hundred nine".