78741381857 has 2 divisors, whose sum is σ = 78741381858. Its totient is φ = 78741381856.

The previous prime is 78741381839. The next prime is 78741381863. The reversal of 78741381857 is 75818314787.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41714386081 + 37026995776 = 204241^2 + 192424^2 .

It is a cyclic number.

It is not a de Polignac number, because 78741381857 - 2⁸ = 78741381601 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 78741381796 and 78741381805.

It is not a weakly prime, because it can be changed into another prime (78741381557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39370690928 + 39370690929.

It is an arithmetic number, because the mean of its divisors is an integer number (39370690929).

Almost surely, 2^78741381857 is an apocalyptic number.

It is an amenable number.

78741381857 is a deficient number, since it is larger than the sum of its proper divisors (1).

78741381857 is an equidigital number, since it uses as much as digits as its factorization.

78741381857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10536960, while the sum is 59.

The spelling of 78741381857 in words is "seventy-eight billion, seven hundred forty-one million, three hundred eighty-one thousand, eight hundred fifty-seven".