666678888 has 24 divisors (see below), whose sum is σ = 1805588850. Its totient is φ = 222226272.

The previous prime is 666678871. The next prime is 666678899. The reversal of 666678888 is 888876666.

It can be written as a sum of positive squares in only one way, i.e., 468376164 + 198302724 = 21642^2 + 14082^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a plaindrome in base 10.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 4629643 + ... + 4629786.

Almost surely, 2^666678888 is an apocalyptic number.

It is an amenable number.

666678888 is an abundant number, since it is smaller than the sum of its proper divisors (1138909962).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

666678888 is a wasteful number, since it uses less digits than its factorization.

666678888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9259441 (or 9259434 counting only the distinct ones).

The product of its digits is 37158912, while the sum is 63.

The square root of 666678888 is about 25820.1256387338. The cubic root of 666678888 is about 873.5858028627.

The spelling of 666678888 in words is "six hundred sixty-six million, six hundred seventy-eight thousand, eight hundred eighty-eight".