78513807391 has 2 divisors, whose sum is σ = 78513807392. Its totient is φ = 78513807390.

The previous prime is 78513807389. The next prime is 78513807443. The reversal of 78513807391 is 19370831587.

It is an a-pointer prime, because the next prime (78513807443) can be obtained adding 78513807391 to its sum of digits (52).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78513807391 - 2¹ = 78513807389 is a prime.

Together with 78513807389, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78513807191) 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, 39256903695 + 39256903696.

It is an arithmetic number, because the mean of its divisors is an integer number (39256903696).

Almost surely, 2^78513807391 is an apocalyptic number.

78513807391 is a deficient number, since it is larger than the sum of its proper divisors (1).

78513807391 is an equidigital number, since it uses as much as digits as its factorization.

78513807391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1270080, while the sum is 52.

The spelling of 78513807391 in words is "seventy-eight billion, five hundred thirteen million, eight hundred seven thousand, three hundred ninety-one".