79866591978785 has 32 divisors (see below), whose sum is σ = 99434141568000. Its totient is φ = 61518428282880.

The previous prime is 79866591978781. The next prime is 79866591978821. The reversal of 79866591978785 is 58787919566897.

It is not a de Polignac number, because 79866591978785 - 2² = 79866591978781 is a prime.

It is not an unprimeable number, because it can be changed into a prime (79866591978781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 51628241 + ... + 53152689.

It is an arithmetic number, because the mean of its divisors is an integer number (3107316924000).

Almost surely, 2^{79866591978785} is an apocalyptic number.

It is an amenable number.

79866591978785 is a deficient number, since it is larger than the sum of its proper divisors (19567549589215).

79866591978785 is a wasteful number, since it uses less digits than its factorization.

79866591978785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1526201.

The product of its digits is 115221657600, while the sum is 95.

The spelling of 79866591978785 in words is "seventy-nine trillion, eight hundred sixty-six billion, five hundred ninety-one million, nine hundred seventy-eight thousand, seven hundred eighty-five".