165700217 has 4 divisors (see below), whose sum is σ = 168416676. Its totient is φ = 162983760.

The previous prime is 165700187. The next prime is 165700231. The reversal of 165700217 is 712007561.

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 55785961 + 109914256 = 7469^2 + 10484^2 .

It is a cyclic number.

It is not a de Polignac number, because 165700217 - 2¹² = 165696121 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 165700217.

It is not an unprimeable number, because it can be changed into a prime (165700237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1358138 + ... + 1358259.

It is an arithmetic number, because the mean of its divisors is an integer number (42104169).

Almost surely, 2^165700217 is an apocalyptic number.

It is an amenable number.

165700217 is a deficient number, since it is larger than the sum of its proper divisors (2716459).

165700217 is an equidigital number, since it uses as much as digits as its factorization.

165700217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2716458.

The product of its (nonzero) digits is 2940, while the sum is 29.

The square root of 165700217 is about 12872.4596328751. The cubic root of 165700217 is about 549.2554299485.

Adding to 165700217 its reverse (712007561), we get a palindrome (877707778).

The spelling of 165700217 in words is "one hundred sixty-five million, seven hundred thousand, two hundred seventeen".