66580416 has 168 divisors, whose sum is σ = 223215200. Its totient is φ = 18966528.

The previous prime is 66580411. The next prime is 66580477. The reversal of 66580416 is 61408566.

66580416 is a `hidden beast` number, since 66 + 580 + 4 + 16 = 666.

It is a tau number, because it is divible by the number of its divisors (168).

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 (66580411) 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, 197400 + ... + 197736.

Almost surely, 2^66580416 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66580416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111607600).

66580416 is an abundant number, since it is smaller than the sum of its proper divisors (156634784).

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

66580416 is a wasteful number, since it uses less digits than its factorization.

66580416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 376 (or 349 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 66580416 is about 8159.6823467584. The cubic root of 66580416 is about 405.3051929140.

The spelling of 66580416 in words is "sixty-six million, five hundred eighty thousand, four hundred sixteen".