66000555 has 16 divisors (see below), whose sum is σ = 117334560. Its totient is φ = 35200224.

The previous prime is 66000553. The next prime is 66000569. The reversal of 66000555 is 55500066.

66000555 is a `hidden beast` number, since 6 + 600 + 0 + 5 + 55 = 666.

It is not a de Polignac number, because 66000555 - 2¹ = 66000553 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (66000553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 244312 + ... + 244581.

It is an arithmetic number, because the mean of its divisors is an integer number (7333410).

Almost surely, 2^66000555 is an apocalyptic number.

66000555 is a deficient number, since it is larger than the sum of its proper divisors (51334005).

66000555 is a wasteful number, since it uses less digits than its factorization.

66000555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 488907 (or 488901 counting only the distinct ones).

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

The square root of 66000555 is about 8124.0725624529. The cubic root of 66000555 is about 404.1251348309.

The spelling of 66000555 in words is "sixty-six million, five hundred fifty-five", and thus it is an aban number.