66199841 has 2 divisors, whose sum is σ = 66199842. Its totient is φ = 66199840.

The previous prime is 66199769. The next prime is 66199843. The reversal of 66199841 is 14899166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49561600 + 16638241 = 7040^2 + 4079^2 .

It is a cyclic number.

It is not a de Polignac number, because 66199841 - 2¹⁰ = 66198817 is a prime.

Together with 66199843, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 66199792 and 66199801.

It is not a weakly prime, because it can be changed into another prime (66199843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33099920 + 33099921.

It is an arithmetic number, because the mean of its divisors is an integer number (33099921).

Almost surely, 2^66199841 is an apocalyptic number.

It is an amenable number.

66199841 is a deficient number, since it is larger than the sum of its proper divisors (1).

66199841 is an equidigital number, since it uses as much as digits as its factorization.

66199841 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 93312, while the sum is 44.

The square root of 66199841 is about 8136.3284717371. The cubic root of 66199841 is about 404.5314726182.

The spelling of 66199841 in words is "sixty-six million, one hundred ninety-nine thousand, eight hundred forty-one".