78047791 has 2 divisors, whose sum is σ = 78047792. Its totient is φ = 78047790.

The previous prime is 78047779. The next prime is 78047803. The reversal of 78047791 is 19774087.

It is a balanced prime because it is at equal distance from previous prime (78047779) and next prime (78047803).

It is an emirp because it is prime and its reverse (19774087) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78047791 - 2¹¹ = 78045743 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78047701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39023895 + 39023896.

It is an arithmetic number, because the mean of its divisors is an integer number (39023896).

Almost surely, 2^78047791 is an apocalyptic number.

78047791 is a deficient number, since it is larger than the sum of its proper divisors (1).

78047791 is an equidigital number, since it uses as much as digits as its factorization.

78047791 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 98784, while the sum is 43.

The square root of 78047791 is about 8834.4660846030. The cubic root of 78047791 is about 427.3531130166.

The spelling of 78047791 in words is "seventy-eight million, forty-seven thousand, seven hundred ninety-one".