863921 has 2 divisors, whose sum is σ = 863922. Its totient is φ = 863920.

The previous prime is 863917. The next prime is 863959. The reversal of 863921 is 129368.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 703921 + 160000 = 839^2 + 400^2 .

It is a cyclic number.

It is not a de Polignac number, because 863921 - 2² = 863917 is a prime.

It is not a weakly prime, because it can be changed into another prime (863521) 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, 431960 + 431961.

It is an arithmetic number, because the mean of its divisors is an integer number (431961).

2⁸⁶³⁹²¹ is an apocalyptic number.

It is an amenable number.

863921 is a deficient number, since it is larger than the sum of its proper divisors (1).

863921 is an equidigital number, since it uses as much as digits as its factorization.

863921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2592, while the sum is 29.

The square root of 863921 is about 929.4735068844. The cubic root of 863921 is about 95.2411601434.

The spelling of 863921 in words is "eight hundred sixty-three thousand, nine hundred twenty-one".