6783421 has 2 divisors, whose sum is σ = 6783422. Its totient is φ = 6783420.

The previous prime is 6783353. The next prime is 6783433. The reversal of 6783421 is 1243876.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3944196 + 2839225 = 1986^2 + 1685^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6783421 is a prime.

It is the 2605-th Hogben number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6783461) by changing a digit.

It is a nontrivial repunit in base 2604.

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, 3391710 + 3391711.

It is an arithmetic number, because the mean of its divisors is an integer number (3391711).

Almost surely, 2^6783421 is an apocalyptic number.

It is an amenable number.

6783421 is a deficient number, since it is larger than the sum of its proper divisors (1).

6783421 is an equidigital number, since it uses as much as digits as its factorization.

6783421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8064, while the sum is 31.

The square root of 6783421 is about 2604.5001439816. The cubic root of 6783421 is about 189.2995539017.

The spelling of 6783421 in words is "six million, seven hundred eighty-three thousand, four hundred twenty-one".