66666888 has 40 divisors (see below), whose sum is σ = 186730830. Its totient is φ = 22222080.

The previous prime is 66666881. The next prime is 66666913. The reversal of 66666888 is 88866666.

It can be written as a sum of positive squares in only one way, i.e., 44595684 + 22071204 = 6678^2 + 4698^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is a plaindrome in base 10.

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (66666881) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 50793 + ... + 52088.

Almost surely, 2^66666888 is an apocalyptic number.

It is an amenable number.

66666888 is an abundant number, since it is smaller than the sum of its proper divisors (120063942).

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

66666888 is a wasteful number, since it uses less digits than its factorization.

66666888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102899 (or 102886 counting only the distinct ones).

The product of its digits is 3981312, while the sum is 54.

The square root of 66666888 is about 8164.9793631093. The cubic root of 66666888 is about 405.4805817691.

The spelling of 66666888 in words is "sixty-six million, six hundred sixty-six thousand, eight hundred eighty-eight".