66785880 has 128 divisors (see below), whose sum is σ = 234432000. Its totient is φ = 14910336.

The previous prime is 66785879. The next prime is 66785891. The reversal of 66785880 is 8858766.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1553139 + ... + 1553181.

It is an arithmetic number, because the mean of its divisors is an integer number (1831500).

Almost surely, 2^66785880 is an apocalyptic number.

66785880 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 66785880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117216000).

66785880 is an abundant number, since it is smaller than the sum of its proper divisors (167646120).

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

66785880 is an equidigital number, since it uses as much as digits as its factorization.

66785880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150 (or 60 counting only the distinct ones).

The product of its (nonzero) digits is 645120, while the sum is 48.

The square root of 66785880 is about 8172.2628445248. The cubic root of 66785880 is about 405.7216823072.

The spelling of 66785880 in words is "sixty-six million, seven hundred eighty-five thousand, eight hundred eighty".