66447321 has 16 divisors (see below), whose sum is σ = 89843904. Its totient is φ = 43678784.

The previous prime is 66447307. The next prime is 66447349. The reversal of 66447321 is 12374466.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 66447321 - 2¹⁸ = 66185177 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66447221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 101431 + ... + 102083.

It is an arithmetic number, because the mean of its divisors is an integer number (5615244).

Almost surely, 2^66447321 is an apocalyptic number.

It is an amenable number.

66447321 is a deficient number, since it is larger than the sum of its proper divisors (23396583).

66447321 is a wasteful number, since it uses less digits than its factorization.

66447321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1080.

The product of its digits is 24192, while the sum is 33.

The square root of 66447321 is about 8151.5226185051. The cubic root of 66447321 is about 405.0349428775.

The spelling of 66447321 in words is "sixty-six million, four hundred forty-seven thousand, three hundred twenty-one".