78447073 has 2 divisors, whose sum is σ = 78447074. Its totient is φ = 78447072.

The previous prime is 78446999. The next prime is 78447077. The reversal of 78447073 is 37074487.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77035729 + 1411344 = 8777^2 + 1188^2 .

It is an emirp because it is prime and its reverse (37074487) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78447073 - 2⁹ = 78446561 is a prime.

It is not a weakly prime, because it can be changed into another prime (78447077) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39223536 + 39223537.

It is an arithmetic number, because the mean of its divisors is an integer number (39223537).

Almost surely, 2^78447073 is an apocalyptic number.

It is an amenable number.

78447073 is a deficient number, since it is larger than the sum of its proper divisors (1).

78447073 is an equidigital number, since it uses as much as digits as its factorization.

78447073 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 131712, while the sum is 40.

The square root of 78447073 is about 8857.0352263046. The cubic root of 78447073 is about 428.0806341367.

The spelling of 78447073 in words is "seventy-eight million, four hundred forty-seven thousand, seventy-three".