66078220 has 24 divisors (see below), whose sum is σ = 149439024. Its totient is φ = 24398016.

The previous prime is 66078217. The next prime is 66078247. The reversal of 66078220 is 2287066.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 126814 + ... + 127333.

It is an arithmetic number, because the mean of its divisors is an integer number (6226626).

Almost surely, 2^66078220 is an apocalyptic number.

It is an amenable number.

66078220 is an abundant number, since it is smaller than the sum of its proper divisors (83360804).

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

66078220 is a wasteful number, since it uses less digits than its factorization.

66078220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 254169 (or 254167 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 66078220 is about 8128.8510873309. The cubic root of 66078220 is about 404.2835884253.

The spelling of 66078220 in words is "sixty-six million, seventy-eight thousand, two hundred twenty".