66688866 has 32 divisors (see below), whose sum is σ = 148780800. Its totient is φ = 22142160.

The previous prime is 66688847. The next prime is 66688873. The reversal of 66688866 is 66888666.

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

It is a zygodrome in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12231 + ... + 16821.

It is an arithmetic number, because the mean of its divisors is an integer number (4649400).

Almost surely, 2^66688866 is an apocalyptic number.

66688866 is an abundant number, since it is smaller than the sum of its proper divisors (82091934).

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

66688866 is a wasteful number, since it uses less digits than its factorization.

66688866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4871 (or 4865 counting only the distinct ones).

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

The square root of 66688866 is about 8166.3251221097. The cubic root of 66688866 is about 405.5251349867.

The spelling of 66688866 in words is "sixty-six million, six hundred eighty-eight thousand, eight hundred sixty-six".