678415649 has 2 divisors, whose sum is σ = 678415650. Its totient is φ = 678415648.

The previous prime is 678415627. The next prime is 678415657. The reversal of 678415649 is 946514876.

678415649 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 520159249 + 158256400 = 22807^2 + 12580^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-678415649 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 678415597 and 678415606.

It is not a weakly prime, because it can be changed into another prime (678415849) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 339207824 + 339207825.

It is an arithmetic number, because the mean of its divisors is an integer number (339207825).

Almost surely, 2^678415649 is an apocalyptic number.

It is an amenable number.

678415649 is a deficient number, since it is larger than the sum of its proper divisors (1).

678415649 is an equidigital number, since it uses as much as digits as its factorization.

678415649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1451520, while the sum is 50.

The square root of 678415649 is about 26046.4133615360. The cubic root of 678415649 is about 878.6824502465.

The spelling of 678415649 in words is "six hundred seventy-eight million, four hundred fifteen thousand, six hundred forty-nine".