660171217 has 16 divisors (see below), whose sum is σ = 732739392. Its totient is φ = 592058880.

The previous prime is 660171191. The next prime is 660171221. The reversal of 660171217 is 712171066.

It is a cyclic number.

It is not a de Polignac number, because 660171217 - 2⁷ = 660171089 is a prime.

It is a super-2 number, since 2×660171217² = 871652071510522178, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (660171227) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18958 + ... + 40984.

It is an arithmetic number, because the mean of its divisors is an integer number (45796212).

Almost surely, 2^660171217 is an apocalyptic number.

It is an amenable number.

660171217 is a deficient number, since it is larger than the sum of its proper divisors (72568175).

660171217 is a wasteful number, since it uses less digits than its factorization.

660171217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22128.

The product of its (nonzero) digits is 3528, while the sum is 31.

The square root of 660171217 is about 25693.7972475849. The cubic root of 660171217 is about 870.7340512859.

The spelling of 660171217 in words is "six hundred sixty million, one hundred seventy-one thousand, two hundred seventeen".