2856509 has 2 divisors, whose sum is σ = 2856510.
Its totient is φ = 2856508.
The previous prime is 2856473. The next prime is 2856521. The reversal of 2856509 is 9056582.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 2630884 + 225625 = 1622^2 + 475^2
It is a cyclic number.
It is not a de Polignac number, because 2856509 - 28 = 2856253 is a prime.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (2856559) 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, 1428254 + 1428255.
It is an arithmetic number, because the mean of its divisors is an integer number (1428255).
22856509 is an apocalyptic number.
It is an amenable number.
2856509 is a deficient number, since it is larger than the sum of its proper divisors (1).
2856509 is an equidigital number, since it uses as much as digits as its factorization.
2856509 is an odious number, because the sum of its binary digits is odd.
The product of its (nonzero) digits is 21600, while the sum is 35.
The square root of 2856509 is about 1690.1210015854.
The cubic root of 2856509 is about 141.8878470386.
The spelling of 2856509 in words is "two million, eight hundred fifty-six thousand, five hundred nine".