66442321 has 4 divisors (see below), whose sum is σ = 72482544. Its totient is φ = 60402100.

The previous prime is 66442301. The next prime is 66442339. The reversal of 66442321 is 12324466.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 66442321 - 2¹¹ = 66440273 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 66442321.

It is not an unprimeable number, because it can be changed into a prime (66442301) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3020095 + ... + 3020116.

It is an arithmetic number, because the mean of its divisors is an integer number (18120636).

Almost surely, 2^66442321 is an apocalyptic number.

It is an amenable number.

66442321 is a deficient number, since it is larger than the sum of its proper divisors (6040223).

66442321 is a wasteful number, since it uses less digits than its factorization.

66442321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6040222.

The product of its digits is 6912, while the sum is 28.

The square root of 66442321 is about 8151.2159215665. The cubic root of 66442321 is about 405.0247833231.

Adding to 66442321 its reverse (12324466), we get a palindrome (78766787).

The spelling of 66442321 in words is "sixty-six million, four hundred forty-two thousand, three hundred twenty-one".