66532321 has 4 divisors (see below), whose sum is σ = 66557700. Its totient is φ = 66506944.

The previous prime is 66532289. The next prime is 66532337. The reversal of 66532321 is 12323566.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13242321 + 53290000 = 3639^2 + 7300^2 .

It is a cyclic number.

It is not a de Polignac number, because 66532321 - 2⁵ = 66532289 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66532321.

It is not an unprimeable number, because it can be changed into a prime (66532391) 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, 8236 + ... + 14173.

It is an arithmetic number, because the mean of its divisors is an integer number (16639425).

Almost surely, 2^66532321 is an apocalyptic number.

It is an amenable number.

66532321 is a deficient number, since it is larger than the sum of its proper divisors (25379).

66532321 is a wasteful number, since it uses less digits than its factorization.

66532321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25378.

The product of its digits is 6480, while the sum is 28.

The square root of 66532321 is about 8156.7347020729. The cubic root of 66532321 is about 405.2075773788.

Adding to 66532321 its reverse (12323566), we get a palindrome (78855887).

The spelling of 66532321 in words is "sixty-six million, five hundred thirty-two thousand, three hundred twenty-one".