6978478909 has 2 divisors, whose sum is σ = 6978478910. Its totient is φ = 6978478908.

The previous prime is 6978478879. The next prime is 6978478979. The reversal of 6978478909 is 9098748796.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4086405625 + 2892073284 = 63925^2 + 53778^2 .

It is a cyclic number.

It is not a de Polignac number, because 6978478909 - 2¹³ = 6978470717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6978478979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3489239454 + 3489239455.

It is an arithmetic number, because the mean of its divisors is an integer number (3489239455).

Almost surely, 2^6978478909 is an apocalyptic number.

It is an amenable number.

6978478909 is a deficient number, since it is larger than the sum of its proper divisors (1).

6978478909 is an equidigital number, since it uses as much as digits as its factorization.

6978478909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54867456, while the sum is 67.

The square root of 6978478909 is about 83537.2905294396. The cubic root of 6978478909 is about 1910.9687719066.

The spelling of 6978478909 in words is "six billion, nine hundred seventy-eight million, four hundred seventy-eight thousand, nine hundred nine".