78321454817 has 8 divisors (see below), whose sum is σ = 82934393256. Its totient is φ = 73709160192.

The previous prime is 78321454811. The next prime is 78321454829. The reversal of 78321454817 is 71845412387.

It can be written as a sum of positive squares in 4 ways, for example, as 49511145121 + 28810309696 = 222511^2 + 169736^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 78321454817 - 2⁶ = 78321454753 is a prime.

It is a super-2 number, since 2×78321454817² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78321454811) 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 7 ways as a sum of consecutive naturals, for example, 101783 + ... + 408659.

It is an arithmetic number, because the mean of its divisors is an integer number (10366799157).

Almost surely, 2^78321454817 is an apocalyptic number.

It is an amenable number.

78321454817 is a deficient number, since it is larger than the sum of its proper divisors (4612938439).

78321454817 is a wasteful number, since it uses less digits than its factorization.

78321454817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321907.

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

The spelling of 78321454817 in words is "seventy-eight billion, three hundred twenty-one million, four hundred fifty-four thousand, eight hundred seventeen".