78643729387 has 2 divisors, whose sum is σ = 78643729388. Its totient is φ = 78643729386.

The previous prime is 78643729349. The next prime is 78643729447. The reversal of 78643729387 is 78392734687.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78643729387 - 2⁷ = 78643729259 is a prime.

It is not a weakly prime, because it can be changed into another prime (78643729687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39321864693 + 39321864694.

It is an arithmetic number, because the mean of its divisors is an integer number (39321864694).

Almost surely, 2^78643729387 is an apocalyptic number.

78643729387 is a deficient number, since it is larger than the sum of its proper divisors (1).

78643729387 is an equidigital number, since it uses as much as digits as its factorization.

78643729387 is an evil number, because the sum of its binary digits is even.

The product of its digits is 85349376, while the sum is 64.

The spelling of 78643729387 in words is "seventy-eight billion, six hundred forty-three million, seven hundred twenty-nine thousand, three hundred eighty-seven".