678732076666 has 24 divisors (see below), whose sum is σ = 1187493395220. Its totient is φ = 290105307072.

The previous prime is 678732076639. The next prime is 678732076679. The reversal of 678732076666 is 666670237876.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 646932271041 + 31799805625 = 804321^2 + 178325^2 .

It is a junction number, because it is equal to n+sod(n) for n = 678732076598 and 678732076607.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9247411 + ... + 9320518.

Almost surely, 2^678732076666 is an apocalyptic number.

678732076666 is a deficient number, since it is larger than the sum of its proper divisors (508761318554).

678732076666 is a wasteful number, since it uses less digits than its factorization.

678732076666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18568318 (or 18568311 counting only the distinct ones).

The product of its (nonzero) digits is 128024064, while the sum is 64.

The spelling of 678732076666 in words is "six hundred seventy-eight billion, seven hundred thirty-two million, seventy-six thousand, six hundred sixty-six".