667778900666 has 8 divisors (see below), whose sum is σ = 1002176044884. Its totient is φ = 333720219040.

The previous prime is 667778900603. The next prime is 667778900749. The reversal of 667778900666 is 666009877766.

It can be written as a sum of positive squares in 2 ways, for example, as 664829867641 + 2949033025 = 815371^2 + 54305^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 667778900596 and 667778900605.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 84610715 + ... + 84618606.

Almost surely, 2^667778900666 is an apocalyptic number.

667778900666 is a deficient number, since it is larger than the sum of its proper divisors (334397144218).

667778900666 is a wasteful number, since it uses less digits than its factorization.

667778900666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169231296.

The product of its (nonzero) digits is 192036096, while the sum is 68.

The spelling of 667778900666 in words is "six hundred sixty-seven billion, seven hundred seventy-eight million, nine hundred thousand, six hundred sixty-six".