66550217 has 8 divisors (see below), whose sum is σ = 71040960. Its totient is φ = 62158320.

The previous prime is 66550199. The next prime is 66550219. The reversal of 66550217 is 71205566.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66550217 - 2¹⁴ = 66533833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66550219) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23318 + ... + 26015.

It is an arithmetic number, because the mean of its divisors is an integer number (8880120).

Almost surely, 2^66550217 is an apocalyptic number.

It is an amenable number.

66550217 is a deficient number, since it is larger than the sum of its proper divisors (4490743).

66550217 is a wasteful number, since it uses less digits than its factorization.

66550217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49423.

The product of its (nonzero) digits is 12600, while the sum is 32.

The square root of 66550217 is about 8157.8316359189. The cubic root of 66550217 is about 405.2439053099.

The spelling of 66550217 in words is "sixty-six million, five hundred fifty thousand, two hundred seventeen".