66606655500 has 576 divisors, whose sum is σ = 267384499200. Its totient is φ = 13836816000.

The previous prime is 66606655487. The next prime is 66606655513. The reversal of 66606655500 is 555660666.

It is an interprime number because it is at equal distance from previous prime (66606655487) and next prime (66606655513).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 16976539 + ... + 16980461.

It is an arithmetic number, because the mean of its divisors is an integer number (464209200).

Almost surely, 2^66606655500 is an apocalyptic number.

66606655500 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 66606655500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133692249600).

66606655500 is an abundant number, since it is smaller than the sum of its proper divisors (200777843700).

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

66606655500 is a wasteful number, since it uses less digits than its factorization.

66606655500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3980 (or 3951 counting only the distinct ones).

The product of its (nonzero) digits is 972000, while the sum is 45.

The spelling of 66606655500 in words is "sixty-six billion, six hundred six million, six hundred fifty-five thousand, five hundred".