78678968321 has 2 divisors, whose sum is σ = 78678968322. Its totient is φ = 78678968320.

The previous prime is 78678968297. The next prime is 78678968371. The reversal of 78678968321 is 12386987687.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54610548721 + 24068419600 = 233689^2 + 155140^2 .

It is a cyclic number.

It is not a de Polignac number, because 78678968321 - 2⁶ = 78678968257 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (78678968371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39339484160 + 39339484161.

It is an arithmetic number, because the mean of its divisors is an integer number (39339484161).

Almost surely, 2^78678968321 is an apocalyptic number.

It is an amenable number.

78678968321 is a deficient number, since it is larger than the sum of its proper divisors (1).

78678968321 is an equidigital number, since it uses as much as digits as its factorization.

78678968321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48771072, while the sum is 65.

The spelling of 78678968321 in words is "seventy-eight billion, six hundred seventy-eight million, nine hundred sixty-eight thousand, three hundred twenty-one".