78789137891 has 2 divisors, whose sum is σ = 78789137892. Its totient is φ = 78789137890.

The previous prime is 78789137837. The next prime is 78789137909. The reversal of 78789137891 is 19873198787.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78789137891 - 2²⁶ = 78722029027 is a prime.

It is not a weakly prime, because it can be changed into another prime (78789137831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39394568945 + 39394568946.

It is an arithmetic number, because the mean of its divisors is an integer number (39394568946).

Almost surely, 2^78789137891 is an apocalyptic number.

78789137891 is a deficient number, since it is larger than the sum of its proper divisors (1).

78789137891 is an equidigital number, since it uses as much as digits as its factorization.

78789137891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 42674688, while the sum is 68.

The spelling of 78789137891 in words is "seventy-eight billion, seven hundred eighty-nine million, one hundred thirty-seven thousand, eight hundred ninety-one".