78520501865 has 16 divisors (see below), whose sum is σ = 104745962496. Its totient is φ = 56113905600.

The previous prime is 78520501861. The next prime is 78520501889. The reversal of 78520501865 is 56810502587.

It is a happy number.

It is not a de Polignac number, because 78520501865 - 2² = 78520501861 is a prime.

It is not an unprimeable number, because it can be changed into a prime (78520501861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19481981 + ... + 19486010.

It is an arithmetic number, because the mean of its divisors is an integer number (6546622656).

Almost surely, 2^78520501865 is an apocalyptic number.

It is an amenable number.

78520501865 is a deficient number, since it is larger than the sum of its proper divisors (26225460631).

78520501865 is a wasteful number, since it uses less digits than its factorization.

78520501865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38968040.

The product of its (nonzero) digits is 672000, while the sum is 47.

The spelling of 78520501865 in words is "seventy-eight billion, five hundred twenty million, five hundred one thousand, eight hundred sixty-five".