863820 has 36 divisors (see below), whose sum is σ = 2620800. Its totient is φ = 230304.

The previous prime is 863803. The next prime is 863833. The reversal of 863820 is 28368.

863820 = 127² + 128² + ... + 166².

863820 is a `hidden beast` number, since 8 + 638 + 20 = 666.

863820 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (36).

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 863820.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2220 + ... + 2579.

It is an arithmetic number, because the mean of its divisors is an integer number (72800).

2⁸⁶³⁸²⁰ is an apocalyptic number.

It is an amenable number.

863820 is an abundant number, since it is smaller than the sum of its proper divisors (1756980).

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

863820 is a wasteful number, since it uses less digits than its factorization.

863820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4814 (or 4809 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 863820 is about 929.4191734627. The cubic root of 863820 is about 95.2374484877.

The spelling of 863820 in words is "eight hundred sixty-three thousand, eight hundred twenty".