78478787773 has 2 divisors, whose sum is σ = 78478787774. Its totient is φ = 78478787772.

The previous prime is 78478787771. The next prime is 78478787789. The reversal of 78478787773 is 37778787487.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 43690196484 + 34788591289 = 209022^2 + 186517^2 .

It is a cyclic number.

It is not a de Polignac number, because 78478787773 - 2¹ = 78478787771 is a prime.

Together with 78478787771, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 78478787696 and 78478787705.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78478787771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39239393886 + 39239393887.

It is an arithmetic number, because the mean of its divisors is an integer number (39239393887).

Almost surely, 2^78478787773 is an apocalyptic number.

It is an amenable number.

78478787773 is a deficient number, since it is larger than the sum of its proper divisors (1).

78478787773 is an equidigital number, since it uses as much as digits as its factorization.

78478787773 is an evil number, because the sum of its binary digits is even.

The product of its digits is 722835456, while the sum is 73.

The spelling of 78478787773 in words is "seventy-eight billion, four hundred seventy-eight million, seven hundred eighty-seven thousand, seven hundred seventy-three".