66517291 has 2 divisors, whose sum is σ = 66517292. Its totient is φ = 66517290.

The previous prime is 66517207. The next prime is 66517303. The reversal of 66517291 is 19271566.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66517291 - 2⁷ = 66517163 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66517291.

It is not a weakly prime, because it can be changed into another prime (66517391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33258645 + 33258646.

It is an arithmetic number, because the mean of its divisors is an integer number (33258646).

Almost surely, 2^66517291 is an apocalyptic number.

66517291 is a deficient number, since it is larger than the sum of its proper divisors (1).

66517291 is an equidigital number, since it uses as much as digits as its factorization.

66517291 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22680, while the sum is 37.

The square root of 66517291 is about 8155.8133254753. The cubic root of 66517291 is about 405.1770622424.

It can be divided in two parts, 665 and 17291, that added together give a square (17956 = 134²).

The spelling of 66517291 in words is "sixty-six million, five hundred seventeen thousand, two hundred ninety-one".