78802320785 has 4 divisors (see below), whose sum is σ = 94562784948. Its totient is φ = 63041856624.

The previous prime is 78802320767. The next prime is 78802320797. The reversal of 78802320785 is 58702320887.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 22084040449 + 56718280336 = 148607^2 + 238156^2 .

It is a cyclic number.

It is not a de Polignac number, because 78802320785 - 2²⁴ = 78785543569 is a prime.

It is a super-2 number, since 2×78802320785² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7880232074 + ... + 7880232083.

It is an arithmetic number, because the mean of its divisors is an integer number (23640696237).

Almost surely, 2^78802320785 is an apocalyptic number.

It is an amenable number.

78802320785 is a deficient number, since it is larger than the sum of its proper divisors (15760464163).

78802320785 is a wasteful number, since it uses less digits than its factorization.

78802320785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15760464162.

The product of its (nonzero) digits is 1505280, while the sum is 50.

It can be divided in two parts, 788023 and 20785, that added together give a palindrome (808808).

The spelling of 78802320785 in words is "seventy-eight billion, eight hundred two million, three hundred twenty thousand, seven hundred eighty-five".