66502217 has 4 divisors (see below), whose sum is σ = 66925956. Its totient is φ = 66078480.

The previous prime is 66502213. The next prime is 66502231. The reversal of 66502217 is 71220566.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7458361 + 59043856 = 2731^2 + 7684^2 .

It is a cyclic number.

It is not a de Polignac number, because 66502217 - 2² = 66502213 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66502217.

It is not an unprimeable number, because it can be changed into a prime (66502211) 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 in 3 ways as a sum of consecutive naturals, for example, 211634 + ... + 211947.

It is an arithmetic number, because the mean of its divisors is an integer number (16731489).

Almost surely, 2^66502217 is an apocalyptic number.

It is an amenable number.

66502217 is a deficient number, since it is larger than the sum of its proper divisors (423739).

66502217 is a wasteful number, since it uses less digits than its factorization.

66502217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 423738.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 66502217 is about 8154.8891470087. The cubic root of 66502217 is about 405.1464531563.

The spelling of 66502217 in words is "sixty-six million, five hundred two thousand, two hundred seventeen".