78328209689 has 2 divisors, whose sum is σ = 78328209690. Its totient is φ = 78328209688.

The previous prime is 78328209683. The next prime is 78328209763. The reversal of 78328209689 is 98690282387.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76443955225 + 1884254464 = 276485^2 + 43408^2 .

It is a cyclic number.

It is not a de Polignac number, because 78328209689 - 2⁸ = 78328209433 is a prime.

It is a super-2 number, since 2×78328209689² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78328209683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39164104844 + 39164104845.

It is an arithmetic number, because the mean of its divisors is an integer number (39164104845).

Almost surely, 2^78328209689 is an apocalyptic number.

It is an amenable number.

78328209689 is a deficient number, since it is larger than the sum of its proper divisors (1).

78328209689 is an equidigital number, since it uses as much as digits as its factorization.

78328209689 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20901888, while the sum is 62.

The spelling of 78328209689 in words is "seventy-eight billion, three hundred twenty-eight million, two hundred nine thousand, six hundred eighty-nine".