66478720 has 256 divisors, whose sum is σ = 211507200. Its totient is φ = 19353600.

The previous prime is 66478697. The next prime is 66478723. The reversal of 66478720 is 2787466.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (66478723) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 936285 + ... + 936355.

It is an arithmetic number, because the mean of its divisors is an integer number (826200).

Almost surely, 2^66478720 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 66478720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105753600).

66478720 is an abundant number, since it is smaller than the sum of its proper divisors (145028480).

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

66478720 is a wasteful number, since it uses less digits than its factorization.

66478720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127 (or 115 counting only the distinct ones).

The product of its (nonzero) digits is 112896, while the sum is 40.

The square root of 66478720 is about 8153.4483502381. The cubic root of 66478720 is about 405.0987312003.

The spelling of 66478720 in words is "sixty-six million, four hundred seventy-eight thousand, seven hundred twenty".