863861 has 4 divisors (see below), whose sum is σ = 872352. Its totient is φ = 855372.

The previous prime is 863851. The next prime is 863867. The reversal of 863861 is 168368.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 863861 - 2¹⁴ = 847477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (863867) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4091 + ... + 4296.

It is an arithmetic number, because the mean of its divisors is an integer number (218088).

2⁸⁶³⁸⁶¹ is an apocalyptic number.

It is an amenable number.

863861 is a deficient number, since it is larger than the sum of its proper divisors (8491).

863861 is a wasteful number, since it uses less digits than its factorization.

863861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8490.

The product of its digits is 6912, while the sum is 32.

The square root of 863861 is about 929.4412299871. The cubic root of 863861 is about 95.2389552343.

The spelling of 863861 in words is "eight hundred sixty-three thousand, eight hundred sixty-one".