855905778 has 112 divisors (see below), whose sum is σ = 2369484096. Its totient is φ = 225698400.

The previous prime is 855905777. The next prime is 855905779. The reversal of 855905778 is 877509558.

It is an interprime number because it is at equal distance from previous prime (855905777) and next prime (855905779).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (855905777) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 129453 + ... + 135903.

It is an arithmetic number, because the mean of its divisors is an integer number (21156108).

Almost surely, 2^855905778 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 855905778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1184742048).

855905778 is an abundant number, since it is smaller than the sum of its proper divisors (1513578318).

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

855905778 is a wasteful number, since it uses less digits than its factorization.

855905778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6491 (or 6476 counting only the distinct ones).

The product of its (nonzero) digits is 3528000, while the sum is 54.

The square root of 855905778 is about 29255.8674115125. The cubic root of 855905778 is about 949.4570408003.

The spelling of 855905778 in words is "eight hundred fifty-five million, nine hundred five thousand, seven hundred seventy-eight".