78644308697 has 2 divisors, whose sum is σ = 78644308698. Its totient is φ = 78644308696.

The previous prime is 78644308663. The next prime is 78644308789. The reversal of 78644308697 is 79680344687.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 52362711241 + 26281597456 = 228829^2 + 162116^2 .

It is an emirp because it is prime and its reverse (79680344687) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78644308697 - 2⁸ = 78644308441 is a prime.

It is not a weakly prime, because it can be changed into another prime (78644308657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39322154348 + 39322154349.

It is an arithmetic number, because the mean of its divisors is an integer number (39322154349).

Almost surely, 2^78644308697 is an apocalyptic number.

It is an amenable number.

78644308697 is a deficient number, since it is larger than the sum of its proper divisors (1).

78644308697 is an equidigital number, since it uses as much as digits as its factorization.

78644308697 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48771072, while the sum is 62.

The spelling of 78644308697 in words is "seventy-eight billion, six hundred forty-four million, three hundred eight thousand, six hundred ninety-seven".