78520315801 has 2 divisors, whose sum is σ = 78520315802. Its totient is φ = 78520315800.

The previous prime is 78520315787. The next prime is 78520315823. The reversal of 78520315801 is 10851302587.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78274610176 + 245705625 = 279776^2 + 15675^2 .

It is an emirp because it is prime and its reverse (10851302587) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78520315801 - 2⁷ = 78520315673 is a prime.

It is not a weakly prime, because it can be changed into another prime (78520325801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39260157900 + 39260157901.

It is an arithmetic number, because the mean of its divisors is an integer number (39260157901).

Almost surely, 2^78520315801 is an apocalyptic number.

It is an amenable number.

78520315801 is a deficient number, since it is larger than the sum of its proper divisors (1).

78520315801 is an equidigital number, since it uses as much as digits as its factorization.

78520315801 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 67200, while the sum is 40.

The spelling of 78520315801 in words is "seventy-eight billion, five hundred twenty million, three hundred fifteen thousand, eight hundred one".