66505800 has 96 divisors (see below), whose sum is σ = 207576000. Its totient is φ = 17614080.

The previous prime is 66505753. The next prime is 66505841. The reversal of 66505800 is 850566.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 119122 + ... + 119678.

It is an arithmetic number, because the mean of its divisors is an integer number (2162250).

Almost surely, 2^66505800 is an apocalyptic number.

66505800 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 66505800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103788000).

66505800 is an abundant number, since it is smaller than the sum of its proper divisors (141070200).

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

66505800 is a wasteful number, since it uses less digits than its factorization.

66505800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 775 (or 766 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 66505800 is about 8155.1088282131. The cubic root of 66505800 is about 405.1537291728.

The spelling of 66505800 in words is "sixty-six million, five hundred five thousand, eight hundred".