66351247 has 2 divisors, whose sum is σ = 66351248. Its totient is φ = 66351246.

The previous prime is 66351203. The next prime is 66351281. The reversal of 66351247 is 74215366.

It is a happy number.

It is an a-pointer prime, because the next prime (66351281) can be obtained adding 66351247 to its sum of digits (34).

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66351247 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66351847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33175623 + 33175624.

It is an arithmetic number, because the mean of its divisors is an integer number (33175624).

Almost surely, 2^66351247 is an apocalyptic number.

66351247 is a deficient number, since it is larger than the sum of its proper divisors (1).

66351247 is an equidigital number, since it uses as much as digits as its factorization.

66351247 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30240, while the sum is 34.

The square root of 66351247 is about 8145.6274773648. The cubic root of 66351247 is about 404.8396398109.

The spelling of 66351247 in words is "sixty-six million, three hundred fifty-one thousand, two hundred forty-seven".