66386880 has 336 divisors, whose sum is σ = 271028160. Its totient is φ = 14598144.

The previous prime is 66386867. The next prime is 66386891. The reversal of 66386880 is 8868366.

66386880 is a `hidden beast` number, since 6 + 638 + 6 + 8 + 8 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (336).

It is a super-2 number, since 2×66386880² = 8814435672268800, 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 polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 745876 + ... + 745964.

Almost surely, 2^66386880 is an apocalyptic number.

66386880 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 66386880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135514080).

66386880 is an abundant number, since it is smaller than the sum of its proper divisors (204641280).

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

66386880 is a wasteful number, since it uses less digits than its factorization.

66386880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156 (or 143 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 45.

The square root of 66386880 is about 8147.8144308765. The cubic root of 66386880 is about 404.9120979783.

The spelling of 66386880 in words is "sixty-six million, three hundred eighty-six thousand, eight hundred eighty".