863840 has 24 divisors (see below), whose sum is σ = 2041200. Its totient is φ = 345472.

The previous prime is 863833. The next prime is 863843. The reversal of 863840 is 48368.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (863843) by changing a digit.

863840 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2540 + ... + 2859.

It is an arithmetic number, because the mean of its divisors is an integer number (85050).

2⁸⁶³⁸⁴⁰ is an apocalyptic number.

863840 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

863840 is an abundant number, since it is smaller than the sum of its proper divisors (1177360).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

863840 is a wasteful number, since it uses less digits than its factorization.

863840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5414 (or 5406 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 863840 is about 929.4299328083. The cubic root of 863840 is about 95.2381834920.

The spelling of 863840 in words is "eight hundred sixty-three thousand, eight hundred forty".