66641249 has 2 divisors, whose sum is σ = 66641250. Its totient is φ = 66641248.

The previous prime is 66641221. The next prime is 66641257. The reversal of 66641249 is 94214666.

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., 62410000 + 4231249 = 7900^2 + 2057^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66641249 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66641209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33320624 + 33320625.

It is an arithmetic number, because the mean of its divisors is an integer number (33320625).

Almost surely, 2^66641249 is an apocalyptic number.

It is an amenable number.

66641249 is a deficient number, since it is larger than the sum of its proper divisors (1).

66641249 is an equidigital number, since it uses as much as digits as its factorization.

66641249 is an evil number, because the sum of its binary digits is even.

The product of its digits is 62208, while the sum is 38.

The square root of 66641249 is about 8163.4091530438. The cubic root of 66641249 is about 405.4285946934.

The spelling of 66641249 in words is "sixty-six million, six hundred forty-one thousand, two hundred forty-nine".