865993 has 2 divisors, whose sum is σ = 865994. Its totient is φ = 865992.

The previous prime is 865979. The next prime is 866003. The reversal of 865993 is 399568.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 727609 + 138384 = 853^2 + 372^2 .

It is a cyclic number.

It is not a de Polignac number, because 865993 - 2⁹ = 865481 is a prime.

It is not a weakly prime, because it can be changed into another prime (865933) 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 as a sum of consecutive naturals, namely, 432996 + 432997.

It is an arithmetic number, because the mean of its divisors is an integer number (432997).

2⁸⁶⁵⁹⁹³ is an apocalyptic number.

It is an amenable number.

865993 is a deficient number, since it is larger than the sum of its proper divisors (1).

865993 is an equidigital number, since it uses as much as digits as its factorization.

865993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 58320, while the sum is 40.

The square root of 865993 is about 930.5874488730. The cubic root of 865993 is about 95.3172404522.

The spelling of 865993 in words is "eight hundred sixty-five thousand, nine hundred ninety-three".