667894456778 has 16 divisors (see below), whose sum is σ = 1013948258400. Its totient is φ = 329911991376.

The previous prime is 667894456739. The next prime is 667894456781. The reversal of 667894456778 is 877654498766.

It is a junction number, because it is equal to n+sod(n) for n = 667894456699 and 667894456708.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6280001 + ... + 6385467.

It is an arithmetic number, because the mean of its divisors is an integer number (63371766150).

Almost surely, 2^667894456778 is an apocalyptic number.

667894456778 is a deficient number, since it is larger than the sum of its proper divisors (346053801622).

667894456778 is a wasteful number, since it uses less digits than its factorization.

667894456778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143701.

The product of its digits is 3413975040, while the sum is 77.

The spelling of 667894456778 in words is "six hundred sixty-seven billion, eight hundred ninety-four million, four hundred fifty-six thousand, seven hundred seventy-eight".