78515138057 has 2 divisors, whose sum is σ = 78515138058. Its totient is φ = 78515138056.

The previous prime is 78515138029. The next prime is 78515138087. The reversal of 78515138057 is 75083151587.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59333165056 + 19181973001 = 243584^2 + 138499^2 .

It is an emirp because it is prime and its reverse (75083151587) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78515138057 - 2¹⁰ = 78515137033 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 78515137996 and 78515138014.

It is not a weakly prime, because it can be changed into another prime (78515138017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39257569028 + 39257569029.

It is an arithmetic number, because the mean of its divisors is an integer number (39257569029).

Almost surely, 2^78515138057 is an apocalyptic number.

It is an amenable number.

78515138057 is a deficient number, since it is larger than the sum of its proper divisors (1).

78515138057 is an equidigital number, since it uses as much as digits as its factorization.

78515138057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1176000, while the sum is 50.

The spelling of 78515138057 in words is "seventy-eight billion, five hundred fifteen million, one hundred thirty-eight thousand, fifty-seven".