1678921415825 has 24 divisors (see below), whose sum is σ = 2206179029880. Its totient is φ = 1265192230400.

The previous prime is 1678921415807. The next prime is 1678921415867. The reversal of 1678921415825 is 5285141298761.

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

It can be written as a sum of positive squares in 12 ways, for example, as 443353559104 + 1235567856721 = 665848^2 + 1111561^2 .

It is not a de Polignac number, because 1678921415825 - 2¹⁰ = 1678921414801 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 28211174 + ... + 28270623.

It is an arithmetic number, because the mean of its divisors is an integer number (91924126245).

Almost surely, 2^{1678921415825} is an apocalyptic number.

It is an amenable number.

1678921415825 is a deficient number, since it is larger than the sum of its proper divisors (527257614055).

1678921415825 is a wasteful number, since it uses less digits than its factorization.

1678921415825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56481877 (or 56481872 counting only the distinct ones).

The product of its digits is 9676800, while the sum is 59.

The spelling of 1678921415825 in words is "one trillion, six hundred seventy-eight billion, nine hundred twenty-one million, four hundred fifteen thousand, eight hundred twenty-five".