79865020816 has 45 divisors (see below), whose sum is σ = 180019738881. Its totient is φ = 34224474816.

The previous prime is 79865020777. The next prime is 79865020841. The reversal of 79865020816 is 61802056897.

The square root of 79865020816 is 282604.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 40699027600 + 39165993216 = 201740^2 + 197904^2 .

It is a super-2 number, since 2×79865020816² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 7907866 + ... + 7917958.

Almost surely, 2^79865020816 is an apocalyptic number.

79865020816 is the 282604-th square number.

It is an amenable number.

79865020816 is an abundant number, since it is smaller than the sum of its proper divisors (100154718065).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

79865020816 is an frugal number, since it uses more digits than its factorization.

79865020816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20208 (or 10102 counting only the distinct ones).

The product of its (nonzero) digits is 1451520, while the sum is 52.

The spelling of 79865020816 in words is "seventy-nine billion, eight hundred sixty-five million, twenty thousand, eight hundred sixteen".