66966780 has 48 divisors (see below), whose sum is σ = 188727840. Its totient is φ = 17741568.

The previous prime is 66966761. The next prime is 66966787. The reversal of 66966780 is 8766966.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66966787) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5866 + ... + 12974.

It is an arithmetic number, because the mean of its divisors is an integer number (3931830).

Almost surely, 2^66966780 is an apocalyptic number.

66966780 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66966780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94363920).

66966780 is an abundant number, since it is smaller than the sum of its proper divisors (121761060).

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

66966780 is a wasteful number, since it uses less digits than its factorization.

66966780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7278 (or 7276 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 48.

The square root of 66966780 is about 8183.3232858051. The cubic root of 66966780 is about 406.0876722667.

The spelling of 66966780 in words is "sixty-six million, nine hundred sixty-six thousand, seven hundred eighty".