6781387 has 2 divisors, whose sum is σ = 6781388. Its totient is φ = 6781386.

The previous prime is 6781381. The next prime is 6781391. The reversal of 6781387 is 7831876.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6781387 is a prime.

It is not a weakly prime, because it can be changed into another prime (6781381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3390693 + 3390694.

It is an arithmetic number, because the mean of its divisors is an integer number (3390694).

Almost surely, 2^6781387 is an apocalyptic number.

6781387 is a deficient number, since it is larger than the sum of its proper divisors (1).

6781387 is an equidigital number, since it uses as much as digits as its factorization.

6781387 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 56448, while the sum is 40.

The square root of 6781387 is about 2604.1096367089. The cubic root of 6781387 is about 189.2806316016.

The spelling of 6781387 in words is "six million, seven hundred eighty-one thousand, three hundred eighty-seven".