78685255849 has 2 divisors, whose sum is σ = 78685255850. Its totient is φ = 78685255848.

The previous prime is 78685255819. The next prime is 78685255867. The reversal of 78685255849 is 94855258687.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 67776915600 + 10908340249 = 260340^2 + 104443^2 .

It is a cyclic number.

It is not a de Polignac number, because 78685255849 - 2¹³ = 78685247657 is a prime.

It is not a weakly prime, because it can be changed into another prime (78685255819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39342627924 + 39342627925.

It is an arithmetic number, because the mean of its divisors is an integer number (39342627925).

Almost surely, 2^78685255849 is an apocalyptic number.

It is an amenable number.

78685255849 is a deficient number, since it is larger than the sum of its proper divisors (1).

78685255849 is an equidigital number, since it uses as much as digits as its factorization.

78685255849 is an evil number, because the sum of its binary digits is even.

The product of its digits is 193536000, while the sum is 67.

The spelling of 78685255849 in words is "seventy-eight billion, six hundred eighty-five million, two hundred fifty-five thousand, eight hundred forty-nine".