66521066 has 8 divisors (see below), whose sum is σ = 100664964. Its totient is φ = 32966080.

The previous prime is 66521047. The next prime is 66521069. The reversal of 66521066 is 66012566.

It can be written as a sum of positive squares in 2 ways, for example, as 53597041 + 12924025 = 7321^2 + 3595^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (66521069) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 146945 + ... + 147396.

Almost surely, 2^66521066 is an apocalyptic number.

66521066 is a deficient number, since it is larger than the sum of its proper divisors (34143898).

66521066 is a wasteful number, since it uses less digits than its factorization.

66521066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 294456.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 66521066 is about 8156.0447522068. The cubic root of 66521066 is about 405.1847269887.

The spelling of 66521066 in words is "sixty-six million, five hundred twenty-one thousand, sixty-six".