66566880 has 192 divisors, whose sum is σ = 245548800. Its totient is φ = 16796160.

The previous prime is 66566879. The next prime is 66566909. The reversal of 66566880 is 8866566.

66566880 is a `hidden beast` number, since 6 + 6 + 566 + 8 + 80 = 666.

It is a super-2 number, since 2×66566880² = 8862299025868800, which contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 81675 + ... + 82485.

It is an arithmetic number, because the mean of its divisors is an integer number (1278900).

Almost surely, 2^66566880 is an apocalyptic number.

66566880 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 66566880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (122774400).

66566880 is an abundant number, since it is smaller than the sum of its proper divisors (178981920).

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

66566880 is a wasteful number, since it uses less digits than its factorization.

66566880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 854 (or 840 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 45.

The square root of 66566880 is about 8158.8528605436. The cubic root of 66566880 is about 405.2777244618.

The spelling of 66566880 in words is "sixty-six million, five hundred sixty-six thousand, eight hundred eighty".