864217 has 4 divisors (see below), whose sum is σ = 866740. Its totient is φ = 861696.

The previous prime is 864211. The next prime is 864221. The reversal of 864217 is 712468.

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 318096 + 546121 = 564^2 + 739^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-864217 is a prime.

It is a Duffinian number.

864217 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (864211) 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, 648 + ... + 1465.

It is an arithmetic number, because the mean of its divisors is an integer number (216685).

2⁸⁶⁴²¹⁷ is an apocalyptic number.

It is an amenable number.

864217 is a deficient number, since it is larger than the sum of its proper divisors (2523).

864217 is a wasteful number, since it uses less digits than its factorization.

864217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2522.

The product of its digits is 2688, while the sum is 28.

The square root of 864217 is about 929.6327231762. The cubic root of 864217 is about 95.2520362013.

It can be divided in two parts, 864 and 217, that added together give a triangular number (1081 = T₄₆).

The spelling of 864217 in words is "eight hundred sixty-four thousand, two hundred seventeen".