78478787771 has 2 divisors, whose sum is σ = 78478787772. Its totient is φ = 78478787770.

The previous prime is 78478787713. The next prime is 78478787773. The reversal of 78478787771 is 17778787487.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78478787771 - 2²² = 78474593467 is a prime.

Together with 78478787773, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 78478787695 and 78478787704.

It is not a weakly prime, because it can be changed into another prime (78478787773) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39239393885 + 39239393886.

It is an arithmetic number, because the mean of its divisors is an integer number (39239393886).

Almost surely, 2^78478787771 is an apocalyptic number.

78478787771 is a deficient number, since it is larger than the sum of its proper divisors (1).

78478787771 is an equidigital number, since it uses as much as digits as its factorization.

78478787771 is an evil number, because the sum of its binary digits is even.

The product of its digits is 240945152, while the sum is 71.

The spelling of 78478787771 in words is "seventy-eight billion, four hundred seventy-eight million, seven hundred eighty-seven thousand, seven hundred seventy-one".