78438847 has 2 divisors, whose sum is σ = 78438848. Its totient is φ = 78438846.

The previous prime is 78438839. The next prime is 78438851. The reversal of 78438847 is 74883487.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78438847 - 2³ = 78438839 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 78438847.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78438047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39219423 + 39219424.

It is an arithmetic number, because the mean of its divisors is an integer number (39219424).

Almost surely, 2^78438847 is an apocalyptic number.

78438847 is a deficient number, since it is larger than the sum of its proper divisors (1).

78438847 is an equidigital number, since it uses as much as digits as its factorization.

78438847 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1204224, while the sum is 49.

The square root of 78438847 is about 8856.5708375195. The cubic root of 78438847 is about 428.0656706959.

The spelling of 78438847 in words is "seventy-eight million, four hundred thirty-eight thousand, eight hundred forty-seven".