1678945717 has 2 divisors, whose sum is σ = 1678945718. Its totient is φ = 1678945716.

The previous prime is 1678945679. The next prime is 1678945727. The reversal of 1678945717 is 7175498761.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1471412881 + 207532836 = 38359^2 + 14406^2 .

It is a cyclic number.

It is not a de Polignac number, because 1678945717 - 2⁷ = 1678945589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1678945727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 839472858 + 839472859.

It is an arithmetic number, because the mean of its divisors is an integer number (839472859).

Almost surely, 2^1678945717 is an apocalyptic number.

It is an amenable number.

1678945717 is a deficient number, since it is larger than the sum of its proper divisors (1).

1678945717 is an equidigital number, since it uses as much as digits as its factorization.

1678945717 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2963520, while the sum is 55.

The square root of 1678945717 is about 40974.9401097793. The cubic root of 1678945717 is about 1188.5356648706.

The spelling of 1678945717 in words is "one billion, six hundred seventy-eight million, nine hundred forty-five thousand, seven hundred seventeen".