78821704351645 has 8 divisors (see below), whose sum is σ = 94945687981056. Its totient is φ = 62817601641936.

The previous prime is 78821704351639. The next prime is 78821704351693. The reversal of 78821704351645 is 54615340712887.

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 78821704351645 - 2⁵ = 78821704351613 is a prime.

It is a super-2 number, since 2×78821704351645² (a number of 29 digits) contains 22 as substring.

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 7 ways as a sum of consecutive naturals, for example, 29970228477 + ... + 29970231106.

It is an arithmetic number, because the mean of its divisors is an integer number (11868210997632).

Almost surely, 2^{78821704351645} is an apocalyptic number.

It is an amenable number.

78821704351645 is a deficient number, since it is larger than the sum of its proper divisors (16123983629411).

78821704351645 is a wasteful number, since it uses less digits than its factorization.

78821704351645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59940459851.

The product of its (nonzero) digits is 45158400, while the sum is 61.

The spelling of 78821704351645 in words is "seventy-eight trillion, eight hundred twenty-one billion, seven hundred four million, three hundred fifty-one thousand, six hundred forty-five".