78394603691 has 2 divisors, whose sum is σ = 78394603692. Its totient is φ = 78394603690.

The previous prime is 78394603681. The next prime is 78394603697. The reversal of 78394603691 is 19630649387.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78394603691 - 2²⁶ = 78327494827 is a prime.

It is a super-2 number, since 2×78394603691² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78394603697) 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, 39197301845 + 39197301846.

It is an arithmetic number, because the mean of its divisors is an integer number (39197301846).

Almost surely, 2^78394603691 is an apocalyptic number.

78394603691 is a deficient number, since it is larger than the sum of its proper divisors (1).

78394603691 is an equidigital number, since it uses as much as digits as its factorization.

78394603691 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5878656, while the sum is 56.

The spelling of 78394603691 in words is "seventy-eight billion, three hundred ninety-four million, six hundred three thousand, six hundred ninety-one".