66565280 has 48 divisors (see below), whose sum is σ = 158918760. Its totient is φ = 26345472.

The previous prime is 66565271. The next prime is 66565307. The reversal of 66565280 is 8256566.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 63425296 + 3139984 = 7964^2 + 1772^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13376 + ... + 17664.

Almost surely, 2^66565280 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 66565280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79459380).

66565280 is an abundant number, since it is smaller than the sum of its proper divisors (92353480).

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

66565280 is a wasteful number, since it uses less digits than its factorization.

66565280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4401 (or 4393 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 38.

The square root of 66565280 is about 8158.7548069543. The cubic root of 66565280 is about 405.2744773538.

The spelling of 66565280 in words is "sixty-six million, five hundred sixty-five thousand, two hundred eighty".