855820 has 24 divisors (see below), whose sum is σ = 2054304. Its totient is φ = 293376.

The previous prime is 855787. The next prime is 855821. The reversal of 855820 is 28558.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is not an unprimeable number, because it can be changed into a prime (855821) by changing a digit.

855820 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 7 ways as a sum of consecutive naturals, for example, 2917 + ... + 3196.

It is an arithmetic number, because the mean of its divisors is an integer number (85596).

2⁸⁵⁵⁸²⁰ is an apocalyptic number.

It is an amenable number.

855820 is an abundant number, since it is smaller than the sum of its proper divisors (1198484).

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

855820 is a wasteful number, since it uses less digits than its factorization.

855820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6129 (or 6127 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 28.

The square root of 855820 is about 925.1053994005. The cubic root of 855820 is about 94.9425321870.

The spelling of 855820 in words is "eight hundred fifty-five thousand, eight hundred twenty".