66656228 has 6 divisors (see below), whose sum is σ = 116648406. Its totient is φ = 33328112.

The previous prime is 66656209. The next prime is 66656243. The reversal of 66656228 is 82265666.

It can be written as a sum of positive squares in only one way, i.e., 64673764 + 1982464 = 8042^2 + 1408^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8332025 + ... + 8332032.

It is an arithmetic number, because the mean of its divisors is an integer number (19441401).

Almost surely, 2^66656228 is an apocalyptic number.

It is an amenable number.

66656228 is a deficient number, since it is larger than the sum of its proper divisors (49992178).

66656228 is a wasteful number, since it uses less digits than its factorization.

66656228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16664061 (or 16664059 counting only the distinct ones).

The product of its digits is 207360, while the sum is 41.

The square root of 66656228 is about 8164.3265490792. The cubic root of 66656228 is about 405.4589685738.

The spelling of 66656228 in words is "sixty-six million, six hundred fifty-six thousand, two hundred twenty-eight".