6781609 has 2 divisors, whose sum is σ = 6781610. Its totient is φ = 6781608.

The previous prime is 6781603. The next prime is 6781633. The reversal of 6781609 is 9061876.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6760000 + 21609 = 2600^2 + 147^2 .

It is a cyclic number.

It is not a de Polignac number, because 6781609 - 2⁹ = 6781097 is a prime.

It is not a weakly prime, because it can be changed into another prime (6781603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3390804 + 3390805.

It is an arithmetic number, because the mean of its divisors is an integer number (3390805).

Almost surely, 2^6781609 is an apocalyptic number.

It is an amenable number.

6781609 is a deficient number, since it is larger than the sum of its proper divisors (1).

6781609 is an equidigital number, since it uses as much as digits as its factorization.

6781609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18144, while the sum is 37.

The square root of 6781609 is about 2604.1522612935. The cubic root of 6781609 is about 189.2826970514.

The spelling of 6781609 in words is "six million, seven hundred eighty-one thousand, six hundred nine".