678856686455 has 16 divisors (see below), whose sum is σ = 824779734240. Its totient is φ = 536350004352.

The previous prime is 678856686419. The next prime is 678856686523. The reversal of 678856686455 is 554686658876.

It is a cyclic number.

It is not a de Polignac number, because 678856686455 - 2²⁰ = 678855637879 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1861364 + ... + 2195993.

It is an arithmetic number, because the mean of its divisors is an integer number (51548733390).

Almost surely, 2^678856686455 is an apocalyptic number.

678856686455 is a deficient number, since it is larger than the sum of its proper divisors (145923047785).

678856686455 is a wasteful number, since it uses less digits than its factorization.

678856686455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4057778.

The product of its digits is 2322432000, while the sum is 74.

The spelling of 678856686455 in words is "six hundred seventy-eight billion, eight hundred fifty-six million, six hundred eighty-six thousand, four hundred fifty-five".