866121 has 8 divisors (see below), whose sum is σ = 1159200. Its totient is φ = 575232.

The previous prime is 866119. The next prime is 866123. The reversal of 866121 is 121668.

It is an interprime number because it is at equal distance from previous prime (866119) and next prime (866123).

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

It is not a de Polignac number, because 866121 - 2¹ = 866119 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 866091 and 866100.

It is not an unprimeable number, because it can be changed into a prime (866123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1026 + ... + 1668.

It is an arithmetic number, because the mean of its divisors is an integer number (144900).

2⁸⁶⁶¹²¹ is an apocalyptic number.

It is an amenable number.

866121 is a deficient number, since it is larger than the sum of its proper divisors (293079).

866121 is a wasteful number, since it uses less digits than its factorization.

866121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1095.

The product of its digits is 576, while the sum is 24.

The square root of 866121 is about 930.6562200942. The cubic root of 866121 is about 95.3219364123.

Adding to 866121 its reverse (121668), we get a palindrome (987789).

The spelling of 866121 in words is "eight hundred sixty-six thousand, one hundred twenty-one".