66132821 has 2 divisors, whose sum is σ = 66132822. Its totient is φ = 66132820.

The previous prime is 66132811. The next prime is 66132929. The reversal of 66132821 is 12823166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50836900 + 15295921 = 7130^2 + 3911^2 .

It is a cyclic number.

It is not a de Polignac number, because 66132821 - 2¹⁰ = 66131797 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66132811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33066410 + 33066411.

It is an arithmetic number, because the mean of its divisors is an integer number (33066411).

Almost surely, 2^66132821 is an apocalyptic number.

It is an amenable number.

66132821 is a deficient number, since it is larger than the sum of its proper divisors (1).

66132821 is an equidigital number, since it uses as much as digits as its factorization.

66132821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3456, while the sum is 29.

The square root of 66132821 is about 8132.2088635253. The cubic root of 66132821 is about 404.3949121007.

Adding to 66132821 its reverse (12823166), we get a palindrome (78955987).

The spelling of 66132821 in words is "sixty-six million, one hundred thirty-two thousand, eight hundred twenty-one".