855990 has 24 divisors (see below), whose sum is σ = 2225808. Its totient is φ = 228240.

The previous prime is 855989. The next prime is 855997. The reversal of 855990 is 99558.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 855990.

It is not an unprimeable number, because it can be changed into a prime (855997) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4666 + ... + 4845.

It is an arithmetic number, because the mean of its divisors is an integer number (92742).

2⁸⁵⁵⁹⁹⁰ is an apocalyptic number.

855990 is an abundant number, since it is smaller than the sum of its proper divisors (1369818).

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

855990 is a wasteful number, since it uses less digits than its factorization.

855990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9524 (or 9521 counting only the distinct ones).

The product of its (nonzero) digits is 16200, while the sum is 36.

The square root of 855990 is about 925.1972762606. The cubic root of 855990 is about 94.9488182292.

It can be divided in two parts, 8559 and 90, that added together give a square (8649 = 93²).

The spelling of 855990 in words is "eight hundred fifty-five thousand, nine hundred ninety".