66533321 has 2 divisors, whose sum is σ = 66533322. Its totient is φ = 66533320.

The previous prime is 66533309. The next prime is 66533329. The reversal of 66533321 is 12333566.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 62980096 + 3553225 = 7936^2 + 1885^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66533321 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a nialpdrome in base 10.

It is not a weakly prime, because it can be changed into another prime (66533329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33266660 + 33266661.

It is an arithmetic number, because the mean of its divisors is an integer number (33266661).

Almost surely, 2^66533321 is an apocalyptic number.

It is an amenable number.

66533321 is a deficient number, since it is larger than the sum of its proper divisors (1).

66533321 is an equidigital number, since it uses as much as digits as its factorization.

66533321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9720, while the sum is 29.

The square root of 66533321 is about 8156.7960008817. The cubic root of 66533321 is about 405.2096074976.

Adding to 66533321 its reverse (12333566), we get a palindrome (78866887).

The spelling of 66533321 in words is "sixty-six million, five hundred thirty-three thousand, three hundred twenty-one".