66755520 has 168 divisors, whose sum is σ = 247412256. Its totient is φ = 16422912.

The previous prime is 66755501. The next prime is 66755527. The reversal of 66755520 is 2555766.

66755520 is a `hidden beast` number, since 66 + 75 + 5 + 520 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66755527) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 36549 + ... + 38331.

It is an arithmetic number, because the mean of its divisors is an integer number (1472692).

Almost surely, 2^66755520 is an apocalyptic number.

66755520 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 66755520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123706128).

66755520 is an abundant number, since it is smaller than the sum of its proper divisors (180656736).

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

66755520 is a wasteful number, since it uses less digits than its factorization.

66755520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1819 (or 1806 counting only the distinct ones).

The product of its (nonzero) digits is 63000, while the sum is 36.

The square root of 66755520 is about 8170.4051307141. The cubic root of 66755520 is about 405.6601943738.

The spelling of 66755520 in words is "sixty-six million, seven hundred fifty-five thousand, five hundred twenty".