678640731826 has 16 divisors (see below), whose sum is σ = 1071558266400. Its totient is φ = 321455318688.

The previous prime is 678640731803. The next prime is 678640731827. The reversal of 678640731826 is 628137046876.

It is not an unprimeable number, because it can be changed into a prime (678640731827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2357041 + ... + 2629243.

It is an arithmetic number, because the mean of its divisors is an integer number (66972391650).

Almost surely, 2^678640731826 is an apocalyptic number.

678640731826 is a deficient number, since it is larger than the sum of its proper divisors (392917534574).

678640731826 is a wasteful number, since it uses less digits than its factorization.

678640731826 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 337833.

The product of its (nonzero) digits is 16257024, while the sum is 58.

The spelling of 678640731826 in words is "six hundred seventy-eight billion, six hundred forty million, seven hundred thirty-one thousand, eight hundred twenty-six".