66178225 has 9 divisors (see below), whose sum is σ = 82111467. Its totient is φ = 52910040.

The previous prime is 66178193. The next prime is 66178279. The reversal of 66178225 is 52287166.

It is a happy number.

The square root of 66178225 is 8135.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 23824161 + 42354064 = 4881^2 + 6508^2 .

It is not a de Polignac number, because 66178225 - 2⁵ = 66178193 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 39862 + ... + 41488.

Almost surely, 2^66178225 is an apocalyptic number.

66178225 is the 8135-th square number.

66178225 is the 4068-th centered octagonal number.

It is an amenable number.

66178225 is a deficient number, since it is larger than the sum of its proper divisors (15933242).

66178225 is an frugal number, since it uses more digits than its factorization.

66178225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3264 (or 1632 counting only the distinct ones).

The product of its digits is 40320, while the sum is 37.

The cubic root of 66178225 is about 404.4874377479.

The spelling of 66178225 in words is "sixty-six million, one hundred seventy-eight thousand, two hundred twenty-five".