66505500 has 72 divisors (see below), whose sum is σ = 209816880. Its totient is φ = 17733600.

The previous prime is 66505499. The next prime is 66505519. The reversal of 66505500 is 550566.

66505500 is a `hidden beast` number, since 6 + 650 + 5 + 5 + 0 + 0 = 666.

It is a congruent number.

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, 2890 + ... + 11889.

Almost surely, 2^66505500 is an apocalyptic number.

66505500 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66505500 is an abundant number, since it is smaller than the sum of its proper divisors (143311380).

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

66505500 is a wasteful number, since it uses less digits than its factorization.

66505500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14804 (or 14789 counting only the distinct ones).

The product of its (nonzero) digits is 4500, while the sum is 27.

The square root of 66505500 is about 8155.0904348143. The cubic root of 66505500 is about 405.1531199713.

The spelling of 66505500 in words is "sixty-six million, five hundred five thousand, five hundred".