1678641785 has 16 divisors (see below), whose sum is σ = 2110397952. Its totient is φ = 1280188800.

The previous prime is 1678641763. The next prime is 1678641799. The reversal of 1678641785 is 5871468761.

It is not a de Polignac number, because 1678641785 - 2²⁴ = 1661864569 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 70436 + ... + 91205.

It is an arithmetic number, because the mean of its divisors is an integer number (131899872).

Almost surely, 2^1678641785 is an apocalyptic number.

It is an amenable number.

1678641785 is a deficient number, since it is larger than the sum of its proper divisors (431756167).

1678641785 is a wasteful number, since it uses less digits than its factorization.

1678641785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161744.

The product of its digits is 2257920, while the sum is 53.

The square root of 1678641785 is about 40971.2311872611. The cubic root of 1678641785 is about 1188.4639421187.

The spelling of 1678641785 in words is "one billion, six hundred seventy-eight million, six hundred forty-one thousand, seven hundred eighty-five".