66678066 has 80 divisors (see below), whose sum is σ = 183927744. Its totient is φ = 17581536.

The previous prime is 66678041. The next prime is 66678071. The reversal of 66678066 is 66087666.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 12481 + ... + 17003.

Almost surely, 2^66678066 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66678066, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91963872).

66678066 is an abundant number, since it is smaller than the sum of its proper divisors (117249678).

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

66678066 is a wasteful number, since it uses less digits than its factorization.

66678066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4557 (or 4548 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 45.

The square root of 66678066 is about 8165.6638431912. The cubic root of 66678066 is about 405.5032427371.

The spelling of 66678066 in words is "sixty-six million, six hundred seventy-eight thousand, sixty-six".