1678921415823 has 16 divisors (see below), whose sum is σ = 2253654620672. Its totient is φ = 1111736340000.

The previous prime is 1678921415807. The next prime is 1678921415867. The reversal of 1678921415823 is 3285141298761.

It is a Cunningham number, because it is equal to 1295732²-1.

It is not a de Polignac number, because 1678921415823 - 2⁴ = 1678921415807 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1678921415023) by changing a digit.

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, 3671238 + ... + 4103148.

It is an arithmetic number, because the mean of its divisors is an integer number (140853413792).

Almost surely, 2^{1678921415823} is an apocalyptic number.

1678921415823 is a deficient number, since it is larger than the sum of its proper divisors (574733204849).

1678921415823 is a wasteful number, since it uses less digits than its factorization.

1678921415823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440646.

The product of its digits is 5806080, while the sum is 57.

The spelling of 1678921415823 in words is "one trillion, six hundred seventy-eight billion, nine hundred twenty-one million, four hundred fifteen thousand, eight hundred twenty-three".