66613201 has 2 divisors, whose sum is σ = 66613202. Its totient is φ = 66613200.

The previous prime is 66613189. The next prime is 66613219. The reversal of 66613201 is 10231666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 43573201 + 23040000 = 6601^2 + 4800^2 .

It is a cyclic number.

It is not a de Polignac number, because 66613201 - 2⁷ = 66613073 is a prime.

It is equal to p_3930334 and since 66613201 and 3930334 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (66613271) 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 as a sum of consecutive naturals, namely, 33306600 + 33306601.

It is an arithmetic number, because the mean of its divisors is an integer number (33306601).

Almost surely, 2^66613201 is an apocalyptic number.

It is an amenable number.

66613201 is a deficient number, since it is larger than the sum of its proper divisors (1).

66613201 is an equidigital number, since it uses as much as digits as its factorization.

66613201 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 66613201 is about 8161.6910625188. The cubic root of 66613201 is about 405.3717077197.

Adding to 66613201 its reverse (10231666), we get a palindrome (76844867).

The spelling of 66613201 in words is "sixty-six million, six hundred thirteen thousand, two hundred one".