78427804891 has 2 divisors, whose sum is σ = 78427804892. Its totient is φ = 78427804890.

The previous prime is 78427804831. The next prime is 78427804901. The reversal of 78427804891 is 19840872487.

It is a strong prime.

It is an emirp because it is prime and its reverse (19840872487) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78427804891 - 2⁹ = 78427804379 is a prime.

It is not a weakly prime, because it can be changed into another prime (78427804831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39213902445 + 39213902446.

It is an arithmetic number, because the mean of its divisors is an integer number (39213902446).

Almost surely, 2^78427804891 is an apocalyptic number.

78427804891 is a deficient number, since it is larger than the sum of its proper divisors (1).

78427804891 is an equidigital number, since it uses as much as digits as its factorization.

78427804891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7225344, while the sum is 58.

The spelling of 78427804891 in words is "seventy-eight billion, four hundred twenty-seven million, eight hundred four thousand, eight hundred ninety-one".