78148640056565 has 16 divisors (see below), whose sum is σ = 100992334279536. Its totient is φ = 57709624627200.

The previous prime is 78148640056559. The next prime is 78148640056639. The reversal of 78148640056565 is 56565004684187.

It can be written as a sum of positive squares in 8 ways, for example, as 1600384393969 + 76548255662596 = 1265063^2 + 8749186^2 .

It is not a de Polignac number, because 78148640056565 - 2⁴⁴ = 60556454012149 is a prime.

It is a super-2 number, since 2×78148640056565² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (65).

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30963335 + ... + 33391995.

It is an arithmetic number, because the mean of its divisors is an integer number (6312020892471).

Almost surely, 2^{78148640056565} is an apocalyptic number.

It is an amenable number.

78148640056565 is a deficient number, since it is larger than the sum of its proper divisors (22843694222971).

78148640056565 is a wasteful number, since it uses less digits than its factorization.

78148640056565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2923720.

The product of its (nonzero) digits is 193536000, while the sum is 65.

The spelling of 78148640056565 in words is "seventy-eight trillion, one hundred forty-eight billion, six hundred forty million, fifty-six thousand, five hundred sixty-five".