66651317 has 2 divisors, whose sum is σ = 66651318. Its totient is φ = 66651316.

The previous prime is 66651283. The next prime is 66651323. The reversal of 66651317 is 71315666.

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., 61606801 + 5044516 = 7849^2 + 2246^2 .

It is a cyclic number.

It is not a de Polignac number, because 66651317 - 2⁶ = 66651253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66651337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33325658 + 33325659.

It is an arithmetic number, because the mean of its divisors is an integer number (33325659).

Almost surely, 2^66651317 is an apocalyptic number.

It is an amenable number.

66651317 is a deficient number, since it is larger than the sum of its proper divisors (1).

66651317 is an equidigital number, since it uses as much as digits as its factorization.

66651317 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22680, while the sum is 35.

The square root of 66651317 is about 8164.0257838887. The cubic root of 66651317 is about 405.4490107251.

The spelling of 66651317 in words is "sixty-six million, six hundred fifty-one thousand, three hundred seventeen".