78678973 has 2 divisors, whose sum is σ = 78678974. Its totient is φ = 78678972.

The previous prime is 78678967. The next prime is 78678989. The reversal of 78678973 is 37987687.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67207204 + 11471769 = 8198^2 + 3387^2 .

It is an emirp because it is prime and its reverse (37987687) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78678973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78678473) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39339486 + 39339487.

It is an arithmetic number, because the mean of its divisors is an integer number (39339487).

Almost surely, 2^78678973 is an apocalyptic number.

It is an amenable number.

78678973 is a deficient number, since it is larger than the sum of its proper divisors (1).

78678973 is an equidigital number, since it uses as much as digits as its factorization.

78678973 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3556224, while the sum is 55.

The square root of 78678973 is about 8870.1168537962. The cubic root of 78678973 is about 428.5020402953.

The spelling of 78678973 in words is "seventy-eight million, six hundred seventy-eight thousand, nine hundred seventy-three".