2788309 has 2 divisors, whose sum is σ = 2788310. Its totient is φ = 2788308.

The previous prime is 2788301. The next prime is 2788327. The reversal of 2788309 is 9038872.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2739025 + 49284 = 1655^2 + 222^2 .

It is a cyclic number.

It is not a de Polignac number, because 2788309 - 2³ = 2788301 is a prime.

2788309 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2788301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1394154 + 1394155.

It is an arithmetic number, because the mean of its divisors is an integer number (1394155).

2^2788309 is an apocalyptic number.

It is an amenable number.

2788309 is a deficient number, since it is larger than the sum of its proper divisors (1).

2788309 is an equidigital number, since it uses as much as digits as its factorization.

2788309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 2788309 is about 1669.8230445170. The cubic root of 2788309 is about 140.7495343904.

The spelling of 2788309 in words is "two million, seven hundred eighty-eight thousand, three hundred nine".